Calcium cyanamide

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

from 2010-03-17 to 2010-11-05

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

Regulation (EC) No 440/2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

adopted 1992-07-17

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples of the test media for determination of the actual test substance concentration were taken immediately before introduction of the fish and after approximately 24, 48 (before and after media change), 72 and 96 hours. The analysis of the test media was stopped when all fish in the respective test media died. For stabilization, the samples were deep frozen immediately after sampling and stored at - 18°C. At the end of the test the samples were transferred on dry ice to the test site.

Vehicle:

no

Details on test solutions:

Dilution water
Local tap water was mixed 1:1 with deionised water to achieve the appropriate water hardness (total hardness: 200 mg CaCO3 /L, determined in the dilution water used for the test).

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish (Danio rerio)
- Source: Tomy's Zoo GmbH / Zoo & Co, Josef-Strebl-Gasse 6, 2345 Brunn am Gebirge, Austria
- Length at study initiation: 3.17, SD: 0.19 (mean of control group at the end of study).
- Weight at study initiation: 0.45, SD: 0.09 (mean of control group at the end of study). As the allocation of the fish to their groups was performed using a randomisation procedure the size and the weight of the control fish is assumed to be representative for the entity of all fish used.
- Feeding during test: none
- Food type: TetraMin; Tetra Werke, Dr.rer.nat. Ulrich Baensch GmbH, D-49304 Melle.
- Frequency: daily

ACCLIMATION
- Acclimation period: Approx. 10 weeks.
- Acclimation conditions (same as test or not): yes
- Type and amount of food: TetraMin; Tetra Werke, Dr.rer.nat. Ulrich Baensch GmbH, D-49304 Melle.
- Feeding frequency: daily

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

none

Hardness:

total hardness: 200 mg CaCO3 /L, determined in the dilution water used for the test

Test temperature:

between 19 °C and 21 °C throughout the test period.

pH:

Due to the basic nature of the test substance the pH in the test media ranged from 7.6 to 11.2. The pH in the control medium was between 8.0 and 8.2 throughout the test period.

Dissolved oxygen:

Dissolved oxygen concentration: At least 82 % of the air saturation value at the appropriate temperature throughout the test period.

Salinity:

not applicable (freshwater)

Nominal and measured concentrations:

Nominal: 0, 25.0, 51.3, 101.0, 200.4, 401.1 mg/L
Measured concentrations confirm the nominal values. For discussion of measured values see below in results section.

Details on test conditions:

Observations in life
All animals were observed for alterations and behavioural changes at introduction of the fish and approximately 2, 4, 24, 48, 72 and 96 hours afterwards. The total lengths of the animals of the control group were determined for documentation of the appropriate size. As the allocation of the fish to their groups was performed using a randomisation procedure the control group was regarded as representative for the entity of all fish used.

Visual observations of the test media
Visual observations were made at the same time as the animal observation. Any change (like change in colour or precipitation) was recorded.

Media change
At 48 hours after the start of the test, media changes were performed. The fish were transferred to duplicate vessel containing the freshly prepared media. The test media as well as the control media were changed.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

ca. 140 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

other: NOEL

Effect conc.:

ca. 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

Unforeseen events
The temperature of the test media decreased to 19 °C which is slightly below the range given by the EC guideline of 20 to 24°C. This deviation is not considered to have affected the outcome of the study as no behavioural changes or mortalities of the animals in the control group was observed. No other unforeseen events occurred.

Animal observation
All fish of group E died within the first 2 hours of exposure. The fish in group D showed decreased mobility after 2 hours of exposure, after 24 hours the first fish died. After 48 hours of exposure the remaining fish in group D showed loss of equilibrium and bleedings around the mouth and the chest, and 3 further dead fish were recorded. The remaining fish in group D were dead 24 hours later. All fish in the other test groups as well as in the control group were inconspicuous in appearance and behaviour throughout the study.

Visual observation of the test and control media
The test media were clear and colourless during the whole time of exposure and so was the control medium.

Results with reference substance (positive control):

no reference substance

Reported statistics and error estimates:

mean and conf. limits (if applicable)

Sublethal observations / clinical signs:

Actual test substance concentrations

Since there is no analytical method available for the detection of the complete test substance, the cyanamide fraction of the test substance was determined analytically. According to the information of the sponsor "CALCIUM CYANAMIDE" contains 36.4 % cyanamide. In the test groups A, B, C, and E cyanamide was stable and the expected cyanamide concentration was found.

In test group D (nominal 200 mg test substance per litre test medium) cyanamide was found to be significantly lower than the target value at several sampling dates, whereby the concentration fluctuates depending on sampling time. To prove, that the target concentration of the test item was used, the calcium concentration of the test solutions was determined within the framework of a second study of the test site. Additionally, the concentration of the degradation product dicyandiamide (DCD) was recalculated from the chromatograms obtained within the first study conducted by the test site.

After 48 hours (before media change) the cyanamide concentration was found to be 69.7 mg/L, which meets almost the target concentration. The back reaction from DCD was never observed and it is unlikely from the chemical point of view. Hence, it is likely, that the cyanamide start concentration and the concentration after 24 hours met the target concentration, too. Dimerisation to DCD probably began after the sampling effected by handling or temperature and concerns only the sample itself.

After 48 hours the medium was prepared anew and was changed. Both solutions (the newly prepared at 48 hours and the solution at 72 hours) contain significant amounts of DCD. Hence, it cannot be differentiated, whether dimerisation started in the test solution or in the sample itself.

However, in all cases it could be stated that the correct amount of "CALCIUM CYANAMIDE" was used and it is very likely (as proven for timepoints 0 and 24 hours) that dimerisation occurred after sampling.

Additionally, the calcium concentration of the test solutions was determined to have a second independent parameter for evaluation. The expected concentration is 91.8 mg/L. Calcium was found to be an unsuitable parameter in this case, because already the blank value (dilution water) is rather high (50.9 mg/L). The sum of cyanamide and DCD concentration in group D nearly complies to the expected cyanamide concentration of 72.8 mg/L.

Apart from test group B the actual test substance equivalents have been satisfactorily maintained to within 80 % of the nominal test substance loading rates (maximum deviation of test group B is 21.8 %).

Validity criteria fulfilled:

yes

Conclusions:

The LD50 (96 h) of Calcium cyanamide, technical grade (Kalkstickstoff) in zebra fish was determined to be 140 mg/L based on nominal concentrations. The NOEL was determined to be 100 mg/L.

Executive summary:

In a 96-h acute toxicity study, Zebrafish (Danio rerio) were exposed to Calcium cyanamide, technical grade (Kalkstickstoff) at nominal concentrations of 0, 25.0, 51.3, 101.0, 200.4, 401.1 mg/L under semi-static conditions (media exchange after 48 h). Calcium cyanamide is a substance with impurities and is of limited solubility in aqueous media. Therefore the fish were exposed to separate preparations of different loading rates of water accommodated fractions (WAFs). Mean nominal loading rates of 25.0, 51.3, 101.0, 200.4, and 401.1 mg per litre were obtained by stirring the respective amount of test substance in dilution water for 60 minutes in the dark at the start of the test as well as 48 hours thereafter. Afterwards not dissolved particles were removed by filtration (0.45 μm) and the clear filtrate was used for the test. The dilution water was local tap water which was mixed 1+1 with deionised water to achieve the appropriate water hardness as required by the guideline. Dilution water was also used for the negative control group. Analytical data supported the use of nominal concentrations for the derivation of reference figures.

All fish of group E (401.1 mg/L) died within the first 2 hours of exposure. The fish in group D (200.4 mg/L) showed decreased mobility after 2 hours of exposure, after 24 hours the first fish died. After 48 hours of exposure the remaining fish in group D showed loss of equilibrium and bleedings around the mouth and the chest, and 3 further dead fish were recorded. The remaining fish in group D were dead 24 hours later. All fish in the other test groups as well as in the control group were inconspicuous in appearance and behaviour throughout the study.

The 96-h LC50 was 140 mg/L. The NOEC value, based on mortality was 100 mg/L.

This toxicity study is classified as acceptable and satisfies the guideline requirement for acute fish toxicity study.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1985-02-11 until 1985-02-15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Committee on Methods for Toxicity Tests with Aquatic Organisms (C.E. Stephan, Chairman) (1975). Methods for Acute Toxicity Tests with Fish, Macroinvertebrates and Amphibians. Environmental Protection Agency, Ecological Research Series EPA 660/3-75-009

Deviations:

yes

Remarks:

see fild below

Qualifier:

according to guideline

Guideline:

other: American Public Health Association (1980). Standard Methods for the Examination of Water and Wastewater. 15th ed. Washington, DC. 1134 p

Deviations:

yes

Remarks:

see fild below

Principles of method if other than guideline:

The areas of deviation from the OECD guideline 203 (adopted 1992) are: Analyses of the test solutions were not performed in this study. Though no analyses of the cyanamide concentration in the test media were performed, it can be assumed that the concentration maintained was stable throughout the whole test, as cyanamide is known to be hydrolytically stable. Furthermore, in the algal inhibition test, the analyses show that no degradation occurred during the test period, which was 96 hours.

GLP compliance:

yes

Analytical monitoring:

no

Details on sampling:

No sampling

Vehicle:

no

Details on test solutions:

not indicated

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

Rainbow trout, Oncorhynchus mykiss (formerly: Salmo gairdneri)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

no post exposure period

Hardness:

not indicated

Test temperature:

Test solutions were maintained between 12.5 and 13.0°C.

pH:

All chemical and physical parameters (dissolved oxygen concentration, pH, temperature) in the definitive test were within expected ranges.

Dissolved oxygen:

All chemical and physical parameters (dissolved oxygen concentration, pH, temperature) in the definitive test were within expected ranges.

Salinity:

Freshwater was used.

Nominal and measured concentrations:

Nominal concentrations of 64.8, 108.0, 180.0, 300.0, and 500.0 mg of a 49% aqueous solution of cyanamide/L.

Details on test conditions:

The acute toxicity of an aqueous solution of Hydrogen cyanamide (a 49% (w/w) aqueous solution of cyanamide) to unfed Rainbow trout, Oncorhynchus mykiss (formerly: Salmo gairdneri), was determined in an unaerated, static, 96-hour test. Treatments consisted of a water control, and nominal concentrations of 64.8, 108.0, 180.0, 300.0, and 500.0 mg of a 49% aqueous solution of cyanamide/L. Test vessels containing 10 fish each were exposed to each treatment concentration and control. Test solutions were maintained between 12.5 and 13.0°C.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

45.6 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

31.8 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Details on results:

All chemical and physical parameters (dissolved oxygen concentration, pH, temperature) in the definitive test were within expected ranges. Analyses of the test solutions were not performed in this study. Mortality or sublethal effects were observed in all treatment groups. The lowest concentration causing 100 % mortality was 180.0 mg of a 49% aqueous solution of cyanamide/L. Surviving fish exhibited effects such as quiescence, hyperexcitability, sounding, dark coloration, varied discoloration, erratic swimming or ceased swimming.

Results with reference substance (positive control):

No reference

Reported statistics and error estimates:

Not indicated

Sublethal observations / clinical signs:

Observed mortality of Rainbow trout,Oncorhynchusmykiss, exposed to a 49% aqueous solution of Cyanamide for 96 hours in an unaerated, static, acute test

 

Nominal concentrations of a 49% (w/w) aqueous solution of cyanamide (mg/L)	Cumulative mortality (No. dead / No. at test start)
	24 h	48 h	72 h	96 h
Water Control	0/10	0/10	0/10	0/10
64.8	0/10	1/10	1/10	1/10
108.0	0/10	1/10	3/10	7/10
180.0	0/10	5/10	10/10	10/10
300.0	2/10	10/10	10/10	10/10
500.0	10/10	10/10	10/10	10/10

 

Observed sublethal effects on rainbow trout,Oncorhynchus mykiss, exposed to a 49% aqueous solution of cyanamide for 96 hours in an unaerated, static, acute test

 

Nominal concentrations of a 49% (w/w) aqueous solution of cyanamide (mg/L)	Sublethal effects (No. affected / No. at test start)
	24 h	48 h	72 h	96 h
Water Control	0/10	0/10	0/10	0/10
64.8	0/10	9d/10	2^d3^f/10	3^d6^d,^g/10
108.0	1^c9^d/10	9^d/10	3^d,^b3^a/10	3^d,^e/10
180.0	1^c9^d/10	5^d,^b/10	L	L
300.0	4^b2^a2^d/10	L	L	L
500.0	L	L	L	L

a   erratic swimming

b   dark discolored

c   ceased swimming

d   quiescent

e   varied discolored

f    hyperexciteable

g   sounding

L   total mortality

Validity criteria fulfilled:

not specified

Conclusions:

The 96-hour LC50 for the Rainbow trout was 93.0 mg of a 49% aqueous solution of cyanamide/L (equivalent to 45.6 mg of as/L, nominal not measured). The observed 96-hour no-effect concentration was less than 64.8 mg of a 49% aqueous solution of cyanamide/L (equivalent to 31.8 mg of as/L).

Executive summary:

The acute toxicity of an aqueous solution of Hydrogen cyanamide (a 49% (w/w) aqueous solution of cyanamide) to unfed Rainbow trout, Oncorhynchus mykiss (formerly: Salmo gairdneri), was determined in an unaerated, static, 96-hour test. Treatments consisted of a water control, and nominal concentrations of 64.8, 108.0, 180.0, 300.0, and 500.0 mg of a 49% aqueous solution of cyanamide/L. Test vessels containing 10 fish each were exposed to each treatment concentration and control. Test solutions were maintained between 12.5 and 13.0°C.

The 96-hour LC50 for the Rainbow trout was 93.0 mg of a 49% aqueous solution of cyanamide/L (equivalent to 45.6 mg of as/L, nominal not measured). The observed 96-hour no-effect concentration was less than 64.8 mg of a 49% aqueous solution of cyanamide/L (equivalent to 31.8 mg of as/L).

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1985-07-18 until 1985-07-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Committee on Methods for Toxicity Tests with Aquatic Organisms (C.E. Stephan, Chairman) (1975). Methods for Acute Toxicity Tests with Fish, Macroinvertebrates and Amphibians. Environmental Protection Agency, Ecological Research Series EPA-660/3-75-009.

Deviations:

yes

Remarks:

, see in the field below

Qualifier:

according to guideline

Guideline:

other: American Public Health Association (1980). Standard Methods for the Examination of Water and Wastewater. 15th ed. Washington, DC. 1134 p.

Deviations:

yes

Remarks:

, see in the field below

Principles of method if other than guideline:

The areas of deviation from the OECD guideline 203 (adopted 1992) are: Analyses of the test solutions were not performed in this study. The fish length of 34±3.6 mm is lower than the recommended fish length of 50±10 mm.
These deviations had no effect on the validity of the study. Though no analyses of the cyanamide concentration in the test media were performed, it can be assumed that the concentration maintained was stable throughout the whole test, as cyanamide is known to be hydrolytically stable. Furthermore, in the algal inhibition test (Seyfried 2000, 823-003; 8.2/09), the analyses show that no degradation occurred during the test period, which was 96 hours.

GLP compliance:

yes

Analytical monitoring:

no

Details on sampling:

No sampling

Vehicle:

no

Details on test solutions:

Not indicated

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

Not indicated

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

No post exposure period

Hardness:

Not indicated

Test temperature:

All chemical and physical parameters (dissolved oxygen concentration, pH, temperature) in the definitive test were within expected ranges. Analyses of the test solutions were not performed in this study.

pH:

All chemical and physical parameters (dissolved oxygen concentration, pH, temperature) in the definitive test were within expected ranges. Analyses of the test solutions were not performed in this study.

Dissolved oxygen:

All chemical and physical parameters (dissolved oxygen concentration, pH, temperature) in the definitive test were within expected ranges. Analyses of the test solutions were not performed in this study.

Salinity:

Freshwater

Nominal and measured concentrations:

Treatments consisted of a water control and nominal concentrations of 31.2, 62.5, 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L.

Details on test conditions:

The acute toxicity of LH 21,810 A (49% (w/w) solution of cyanamide) to unfed fingerling rainbow trout, Oncorhynchus mykiss (formerly: Salmo gairdneri), was determined in an unaerated, static, 96-hour test. Treatments consisted of a water control, and nominal concentrations of 31.2, 62.5, 125.0, 250.0, 500.0, and 1000.0 mg of a 49% aqueous solution of cyanamide/L. Test vessels containing 10 fish each were exposed to each treatment concentration and control. Test solutions were maintained between 11 and 13°C.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

88.2 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: lack of mortality and abnormal effects

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

30.6 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: lack of mortality and abnormal effects

Details on results:

There were no mortality below 125.0 mg of a 49% aqueous solution of cyanamide/L and the lowest concentration causing 100% mortality was 250.0 mg of a 49% aqueous solution of cyanamide /L. Surviving fish exhibited effects such as loss of equilibrium, dark discoloration and/or they were found on the bottom of test chambers at the test concentration of 125.0, 250.0, 500.0, and 1000.0 mg of a 49% aqueous solution of cyanamide /L during the 96-hour exposure period.

Results with reference substance (positive control):

No positive control

Reported statistics and error estimates:

Not indicated

Sublethal observations / clinical signs:

Observed mortality of rainbow trout,Oncorhynchus mykiss, exposed to a 49% aqueous solution of cyanamide for 96 hours in an unaerated, static, acute test:

Nominal concentrations of a 49% aqueous solution of cyanamide (mg/L)	Cumulative mortality (No. dead / No. at test start)
	24 h^a	48 h^a	96 h^a
Water Control	0/10	0/10	0/10
31.2	0/10	0/10	0/10
62.5	0/10	0/10	0/10
125.0	0/10	0/10	0/10
250.0	0/10	0/10	10/10
500.0	0/10	10/10	10/10
1000.0	10/10	10/10	10/10

Acute toxicity to rainbow trout–Summary of endpoints:

Test substance	49 % (w/w) aqueous solution of Cyanamide
Test object	Rainbow trout (Oncorhynchus mykiss)
Test duration	96 h
LC50	180.0 mg/L
	88.2 mg of the pure ai/L
No observed effect concentration (NOEC)	62.5 mg/L
	30.6 mg of the pure ai/L

Validity criteria fulfilled:

not specified

Conclusions:

The 96-hour LC50 for the rainbow trout was 180.0 mg of a 49% aqueous solution of cyanamide/L (equivalent to 88.2 mg of the pure ai/L). The results indicated a 96-hour NOEC (no observed effect concentration) of 62.5 mg of a 49% aqueous solution of cyanamide/L (equivalent to 30.6 mg of the pure ai/L), which was based on the lack of mortality and abnormal effects.

Executive summary:

The acute toxicity of LH 21.810 (a 49% (w/w) aqueous solution of cyanamide) to unfed fingerling rainbow trout, Oncorhynchus mykiss (formerly: Salmo gairdneri) was determined in a static, 96-hour test. Treatments consisted of a water control and nominal concentrations of 31.2, 62.5, 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Test vessels containing 10 fish each were exposed to each treatment concentration and control. There were no mortality below 125.0 mg of a 49% aqueous solution of cyanamide/L and the lowest concentration causing 100% mortality was 250.0 mg of a 49% aqueous solution of cyanamide /L. Surviving fish exhibited effects such as loss of equilibrium, dark discoloration and/or they were found on the bottom of test chambers at the test concentration of 125.0, 250.0, 500.0, and 1000.0 mg of a 49% aqueous solution of cyanamide /L during the 96-hour exposure period. The 96-hour LC50 for the rainbow trout was 180.0 mg of a 49% aqueous solution of cyanamide/L (equivalent to 88.2 mg of the pure ai/L). The results indicated a 96-hour NOEC (no observed effect concentration) of 62.5 mg of a 49% aqueous solution of cyanamide/L (equivalent to 30.6 mg of the pure ai/L), which was based on the lack of mortality and abnormal effects.

Reference 4

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1985

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Committee on Methods for Toxicity Tests with Aquatic Organisms (C.E. Stephan, Chairman) (1975). Methods for Acute Toxicity Tests with Fish, Macroinvertebrates and Amphibians. Environmental Protection Agency, Ecological Research Series EPA-660/3-75-009.

Deviations:

yes

Remarks:

, see in the field below

Qualifier:

according to guideline

Guideline:

other: American Public Health Association (1980). Standard Methods for the Examination of Water and Wastewater. 15th ed. Washington, DC. 1134 p.

Deviations:

yes

Remarks:

, see in the field below

Principles of method if other than guideline:

The areas of deviation from the OECD guideline 203 (adopted 1992) are: Analyses of the test solutions were not performed in this study. Though no analyses of the cyanamide concentration in the test media were performed, it can be assumed that the concentration maintained was stable throughout the whole test, as cyanamide is known to be hydrolytically stable. Furthermore, in the algal inhibition test (Doc. No. 823-003) the analyses show that no degradation occurred during the test period, which was 96 hours.

GLP compliance:

yes

Analytical monitoring:

no

Details on sampling:

No sampling

Vehicle:

no

Details on test solutions:

Not indicated

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

Not indicated

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

No post exposure period

Hardness:

Not indicated

Test temperature:

Test solutions were maintained at 22°C

pH:

All chemical and physical parameters (dissolved oxygen concentration, pH, temperature) in the definitive test were within expected ranges. Analyses of the test solutions were not performed in this study.

Dissolved oxygen:

All chemical and physical parameters (dissolved oxygen concentration, pH, temperature) in the definitive test were within expected ranges. Analyses of the test solutions were not performed in this study.

Salinity:

Freshwater

Nominal and measured concentrations:

Treatments consisted of a water control and nominal concentrations of 31.2, 62.5, 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of Cyanamide/L.

Details on test conditions:

The acute toxicity of LH 21.810 (a 49% (w/w) aqueous solution of cyanamide) to unfed juvenile Bluegill sunfish, Lepomis macrochirus, was determined in a static, 96-hour test. Treatments consisted of a water control and nominal concentrations of 31.2, 62.5, 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Test vessels containing 10 fish each were exposed to each treatment concentration and control. Test solutions were maintained at 22°.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

43.1 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: lack of mortality and abnormal effects

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

30.6 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: lack of mortality and abnormal effects

Details on results:

There was no mortality below 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The highest concentration causing no mortality was 62.5 mg of a 49% (w/w) aqueous solution of cyanamide/L and the lowest concentration causing 100 % mortality was 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The abnormal effects of loss of equilibrium, fish on the bottom of test chambers and/or quiescence were observed in the 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L test concentrations.

Results with reference substance (positive control):

No positive control

Reported statistics and error estimates:

Not indicated

Sublethal observations / clinical signs:

Mortality of Bluegill sunfish,Lepomis macrochirus, exposed to a 49% (w/w) aqueous solution of cyanamide for 96 hours in an unaerated, static, acute test

Nominal concentrations of the 49% (w/w) aqueous solution of cyanamide (mg/L)	Cumulative mortality (No. dead / No. at test start)
	24 h	48 h	96 h
Water Control	0/10	0/10	0/10
31.2	0/10	0/10	0/10
62.5	0/10	0/10	0/10
125.0	0/10	0/10	10/10
250.0	0/10	0/10	10/10
500.0	5/10	10/10	10/10
1000.0	10/10	10/10	10/10

Acute toxicity (96 h) of Cyanamide toLepomis macrochirus–Summary of endpoints:

Endpoint	Nominal concentration of 49 % (w/w) aqueous solution of Cyanamide
LC50	88.0 mg/L (43.1 mg as/L)
No observed effect concentration (NOEC)	62.5 mg/L (30.6 mg as/L)

Validity criteria fulfilled:

not specified

Conclusions:

The 96-hour LC50 in the Bluegill sunfish was 88.0 mg of a 49% (w/w) aqueous solution of cyanamide/L (equivalent to 43.1 mg as/L, nominal-not measured). The results indicated a 96-hour, NOEC (no observed effect concentration) of 62.5 mg of a 49% (w/w) aqueous solution of cyanamide/L (equivalent to 30.6 mg of the pure as/L), which was based on the lack of mortality and abnormal effects.

Executive summary:

The acute toxicity of LH 21.810 (a 49% (w/w) aqueous solution of cyanamide) to unfed juvenile Bluegill sunfish, Lepomis macrochirus, was determined in a static, 96-hour test. Treatments consisted of a water control and nominal concentrations of 31.2, 62.5, 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Test vessels containing 10 fish each were exposed to each treatment concentration and control. Test solutions were maintained at 22°C. There was no mortality below 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The highest concentration causing no mortality was 62.5 mg of a 49% (w/w) aqueous solution of cyanamide/L and the lowest concentration causing 100 % mortality was 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The abnormal effects of loss of equilibrium, fish on the bottom of test chambers and/or quiescence were observed in the 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L test concentrations. The 96-hour LC50 in the Bluegill sunfish was 88.0 mg of a 49% (w/w) aqueous solution of cyanamide/L (equivalent to 43.1 mg as/L, nominal-not measured). The results indicated a 96-hour, NOEC (no observed effect concentration) of 62.5 mg of a 49% (w/w) aqueous solution of cyanamide/L (equivalent to 30.6 mg of the pure as/L), which was based on the lack of mortality and abnormal effects.

Reference 5

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1990

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPP 72-1 (Fish Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Mean measured concentrations of the 49% (w/w) aqueous solution of cyanamide were 61.0, 117.0, 232.0, 476.0, and 1040.0 mg/L and ranged from 93 to 104 % of nominal concentrations. In the test medium the test item was sufficiently stable during the test period of 96 hours.

Vehicle:

no

Details on test solutions:

Treatments consisted of a water control and nominal concentrations of 63.0, 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

Not indicated

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

No post exposure observation period

Hardness:

Not indicated

Test temperature:

22°C

pH:

All chemical and physical parameters (dissolved oxygen concentration, pH, temperature) in the definitive test were within expected ranges.

Dissolved oxygen:

All chemical and physical parameters (dissolved oxygen concentration, pH, temperature) in the definitive test were within expected ranges.

Salinity:

Freshwater

Nominal and measured concentrations:

Nominal concentrations of 63.0, 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L.
Mean measured concentrations of the 49% (w/w) aqueous solution of cyanamide were 61.0, 117.0, 232.0, 476.0, and 1040.0 mg/L .

Details on test conditions:

Test vessels containing 10 fish each

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

80.9 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

29.9 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

behaviour

Remarks on result:

other: The NOEC concentration, based on mean measured concentrations, was estimated to be 61.0 mg of the 49% aqueous solution of cyanamide/L (equivalent to 29.9 mg as/L).

Details on results:

There were no mortality below 250.0 mg of a 49% (w/w) aqueous solution of cyanamide/L and no sublethal effects below 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The highest concentration causing no mortality was 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L and the lowest concentration causing 100 % mortality was 250.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Behavioural/sublethal effects noted during the study included surfacing, erratic swimming, pectoral fins retracted and immobile, fish on bottom of test aquaria, defecating and quiescence. These effects were noted among the fish at test concentration of 125.0, 250.0, and 500.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Therefore, a no-effect concentration - based on mean measured concentrations - was determined to be 61.0 mg of a 49% (w/w) aqueous solution of cyanamide/L.

Results with reference substance (positive control):

No positive control

Reported statistics and error estimates:

Not indicated

Sublethal observations / clinical signs:

No other information

Validity criteria fulfilled:

not specified

Conclusions:

The 96-hour LC50 to Carp was 165.0 mg of the 49% (w/w) aqueous solution of cyanamide/L (equivalent to 80.9 mg as/L). The no-observed effect concentration was estimated to be 61.0 mg of the 49% aqueous solution of cyanamide/L (equivalent to 29.9 mg as/L).

Executive summary:

The acute toxicity of a 49% aqueous solution of cyanamide to unfed juvenile Carp, Cyprinus carpio, was determined in a flow-through, 96-hour test. Treatments consisted of a water control and nominal concentrations of 63.0, 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Test vessels containing 10 fish each were exposed to each treatment concentration and control. Test solutions were maintained at 22°C. The samples of the test medium were analysed using an UV-VIS Spectrophotometer. Mean measured concentrations of the 49% (w/w) aqueous solution of cyanamide were 61.0, 117.0, 232.0, 476.0, and 1040.0 mg/L and ranged from 93 to 104 % of nominal concentrations. In the test medium the test item was sufficiently stable during the test period of 96 hours. There were no mortality below 250.0 mg of a 49% (w/w) aqueous solution of cyanamide/L and no sublethal effects below 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The highest concentration causing no mortality was 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L and the lowest concentration causing 100 % mortality was 250.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Behavioural/sublethal effects noted during the study included surfacing, erratic swimming, pectoral fins retracted and immobile, fish on bottom of test aquaria, defecating and quiescence. These effects were noted among the fish at test concentration of 125.0, 250.0, and 500.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Therefore, a no-effect concentration - based on mean measured concentrations - was determined to be 61.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The 96-hour LC50 to Carp was 165.0 mg of the 49% (w/w) aqueous solution of cyanamide/L (equivalent to 80.9 mg as/L). The no-observed effect concentration was estimated to be 61.0 mg of the 49% aqueous solution of cyanamide/L (equivalent to 29.9 mg as/L).

Reference 6

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Justification for type of information:

Upon dissolution in water calcium cyanamide is fast transformed to hydrogen cyanamide.
Therefore, ecotoxicity in natural aquatic environments can be expressed in terms of cyanamide, irrespective of the substance constituting the exposure source. This is supported by experimental results: After stoichiometric correction of test concentrations, toxic effect values of cyanamide and calcium cyanamide are very similar in all standard test organisms. Thus, read-across from cyanamide to calcium cyanamide is justified for aquatic environmental endpoints.
For agricultural applications, calcium cyanamide is formulated as granules (PERLKA) that only slowly dissolve in a soil environment. Exposure of the aquatic environment will be exclusively due to runoff from agricultural fields. As above, cyanamide is the chemical moiety relevant for exposure due to rapid transformation from calcium cyanamide to cyanamide.
(Please note: direct release of the product to surface waters is strictly advised against, thus not a relevant exposure pathway.)

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

45.6 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

31.8 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Details on results:

All chemical and physical parameters (dissolved oxygen concentration, pH, temperature) in the definitive test were within expected ranges. Analyses of the test solutions were not performed in this study. Mortality or sublethal effects were observed in all treatment groups. The lowest concentration causing 100 % mortality was 180.0 mg of a 49% aqueous solution of cyanamide/L. Surviving fish exhibited effects such as quiescence, hyperexcitability, sounding, dark coloration, varied discoloration, erratic swimming or ceased swimming.

Results with reference substance (positive control):

No reference

Reported statistics and error estimates:

Not indicated

Sublethal observations / clinical signs:

Observed mortality of Rainbow trout,Oncorhynchusmykiss, exposed to a 49% aqueous solution of Cyanamide for 96 hours in an unaerated, static, acute test

 

Nominal concentrations of a 49% (w/w) aqueous solution of cyanamide (mg/L)	Cumulative mortality (No. dead / No. at test start)
	24 h	48 h	72 h	96 h
Water Control	0/10	0/10	0/10	0/10
64.8	0/10	1/10	1/10	1/10
108.0	0/10	1/10	3/10	7/10
180.0	0/10	5/10	10/10	10/10
300.0	2/10	10/10	10/10	10/10
500.0	10/10	10/10	10/10	10/10

 

Observed sublethal effects on rainbow trout,Oncorhynchus mykiss, exposed to a 49% aqueous solution of cyanamide for 96 hours in an unaerated, static, acute test

 

Nominal concentrations of a 49% (w/w) aqueous solution of cyanamide (mg/L)	Sublethal effects (No. affected / No. at test start)
	24 h	48 h	72 h	96 h
Water Control	0/10	0/10	0/10	0/10
64.8	0/10	9d/10	2^d3^f/10	3^d6^d,^g/10
108.0	1^c9^d/10	9^d/10	3^d,^b3^a/10	3^d,^e/10
180.0	1^c9^d/10	5^d,^b/10	L	L
300.0	4^b2^a2^d/10	L	L	L
500.0	L	L	L	L

a   erratic swimming

b   dark discolored

c   ceased swimming

d   quiescent

e   varied discolored

f    hyperexciteable

g   sounding

L   total mortality

Validity criteria fulfilled:

not specified

Conclusions:

The 96-hour LC50 for the Rainbow trout was 93.0 mg of a 49% aqueous solution of cyanamide/L (equivalent to 45.6 mg of as/L, nominal not measured). The observed 96-hour no-effect concentration was less than 64.8 mg of a 49% aqueous solution of cyanamide/L (equivalent to 31.8 mg of as/L).

Upon dissolution in water calcium cyanamide is fast transformed to hydrogen cyanamide.
Therefore, ecotoxicity in natural aquatic environments can be expressed in terms of cyanamide, irrespective of the substance constituting the exposure source. This is supported by experimental results: After stoichiometric correction of test concentrations, toxic effect values of cyanamide and calcium cyanamide are very similar in all standard test organisms. Thus, read-across from cyanamide to calcium cyanamide is justified for aquatic environmental endpoints.
For agricultural applications, calcium cyanamide is formulated as granules (PERLKA) that only slowly dissolve in a soil environment. Exposure of the aquatic environment will be exclusively due to runoff from agricultural fields. As above, cyanamide is the chemical moiety relevant for exposure due to rapid transformation from calcium cyanamide to cyanamide
(Please note: direct release of the product to surface waters is strictly advised against, thus not a relevant exposure pathway.)

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Executive summary:

The acute toxicity of an aqueous solution of Hydrogen cyanamide (a 49% (w/w) aqueous solution of cyanamide) to unfed Rainbow trout, Oncorhynchus mykiss (formerly: Salmo gairdneri), was determined in an unaerated, static, 96-hour test. Treatments consisted of a water control, and nominal concentrations of 64.8, 108.0, 180.0, 300.0, and 500.0 mg of a 49% aqueous solution of cyanamide/L. Test vessels containing 10 fish each were exposed to each treatment concentration and control. Test solutions were maintained between 12.5 and 13.0°C.

The 96-hour LC50 for the Rainbow trout was 93.0 mg of a 49% aqueous solution of cyanamide/L (equivalent to 45.6 mg of as/L, nominal not measured). The observed 96-hour no-effect concentration was less than 64.8 mg of a 49% aqueous solution of cyanamide/L (equivalent to 31.8 mg of as/L).

This information is used in a read-across approach in the assessment of the target substance.

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Reference 7

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Justification for type of information:

Upon dissolution in water calcium cyanamide is fast transformed to hydrogen cyanamide.
Therefore, ecotoxicity in natural aquatic environments can be expressed in terms of cyanamide, irrespective of the substance constituting the exposure source. This is supported by experimental results: After stoichiometric correction of test concentrations, toxic effect values of cyanamide and calcium cyanamide are very similar in all standard test organisms. Thus, read-across from cyanamide to calcium cyanamide is justified for aquatic environmental endpoints.
For agricultural applications, calcium cyanamide is formulated as granules (PERLKA) that only slowly dissolve in a soil environment. Exposure of the aquatic environment will be exclusively due to runoff from agricultural fields. As above, cyanamide is the chemical moiety relevant for exposure due to rapid transformation from calcium cyanamide to cyanamide.
(Please note: direct release of the product to surface waters is strictly advised against, thus not a relevant exposure pathway.)

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

88.2 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: lack of mortality and abnormal effects

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

30.6 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: lack of mortality and abnormal effects

Details on results:

There were no mortality below 125.0 mg of a 49% aqueous solution of cyanamide/L and the lowest concentration causing 100% mortality was 250.0 mg of a 49% aqueous solution of cyanamide /L. Surviving fish exhibited effects such as loss of equilibrium, dark discoloration and/or they were found on the bottom of test chambers at the test concentration of 125.0, 250.0, 500.0, and 1000.0 mg of a 49% aqueous solution of cyanamide /L during the 96-hour exposure period.

Results with reference substance (positive control):

No positive control

Reported statistics and error estimates:

Not indicated

Sublethal observations / clinical signs:

Observed mortality of rainbow trout,Oncorhynchus mykiss, exposed to a 49% aqueous solution of cyanamide for 96 hours in an unaerated, static, acute test:

Nominal concentrations of a 49% aqueous solution of cyanamide (mg/L)	Cumulative mortality (No. dead / No. at test start)
	24 h^a	48 h^a	96 h^a
Water Control	0/10	0/10	0/10
31.2	0/10	0/10	0/10
62.5	0/10	0/10	0/10
125.0	0/10	0/10	0/10
250.0	0/10	0/10	10/10
500.0	0/10	10/10	10/10
1000.0	10/10	10/10	10/10

Acute toxicity to rainbow trout–Summary of endpoints:

Test substance	49 % (w/w) aqueous solution of Cyanamide
Test object	Rainbow trout (Oncorhynchus mykiss)
Test duration	96 h
LC50	180.0 mg/L
	88.2 mg of the pure ai/L
No observed effect concentration (NOEC)	62.5 mg/L
	30.6 mg of the pure ai/L

Validity criteria fulfilled:

not specified

Conclusions:

The 96-hour LC50 for the rainbow trout was 180.0 mg of a 49% aqueous solution of cyanamide/L (equivalent to 88.2 mg of the pure ai/L). The results indicated a 96-hour NOEC (no observed effect concentration) of 62.5 mg of a 49% aqueous solution of cyanamide/L (equivalent to 30.6 mg of the pure ai/L), which was based on the lack of mortality and abnormal effects.

Upon dissolution in water calcium cyanamide is fast transformed to hydrogen cyanamide.
Therefore, ecotoxicity in natural aquatic environments can be expressed in terms of cyanamide, irrespective of the substance constituting the exposure source. This is supported by experimental results: After stoichiometric correction of test concentrations, toxic effect values of cyanamide and calcium cyanamide are very similar in all standard test organisms. Thus, read-across from cyanamide to calcium cyanamide is justified for aquatic environmental endpoints.
For agricultural applications, calcium cyanamide is formulated as granules (PERLKA) that only slowly dissolve in a soil environment. Exposure of the aquatic environment will be exclusively due to runoff from agricultural fields. As above, cyanamide is the chemical moiety relevant for exposure due to rapid transformation from calcium cyanamide to cyanamide
(Please note: direct release of the product to surface waters is strictly advised against, thus not a relevant exposure pathway.)

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Executive summary:

The acute toxicity of LH 21.810 (a 49% (w/w) aqueous solution of cyanamide) to unfed fingerling rainbow trout, Oncorhynchus mykiss (formerly: Salmo gairdneri) was determined in a static, 96-hour test. Treatments consisted of a water control and nominal concentrations of 31.2, 62.5, 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Test vessels containing 10 fish each were exposed to each treatment concentration and control. There were no mortality below 125.0 mg of a 49% aqueous solution of cyanamide/L and the lowest concentration causing 100% mortality was 250.0 mg of a 49% aqueous solution of cyanamide /L. Surviving fish exhibited effects such as loss of equilibrium, dark discoloration and/or they were found on the bottom of test chambers at the test concentration of 125.0, 250.0, 500.0, and 1000.0 mg of a 49% aqueous solution of cyanamide /L during the 96-hour exposure period. The 96-hour LC50 for the rainbow trout was 180.0 mg of a 49% aqueous solution of cyanamide/L (equivalent to 88.2 mg of the pure ai/L). The results indicated a 96-hour NOEC (no observed effect concentration) of 62.5 mg of a 49% aqueous solution of cyanamide/L (equivalent to 30.6 mg of the pure ai/L), which was based on the lack of mortality and abnormal effects.

This information is used in a read-across approach in the assessment of the target substance.

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Reference 8

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Upon dissolution in water calcium cyanamide is fast transformed to hydrogen cyanamide.
Therefore, ecotoxicity in natural aquatic environments can be expressed in terms of cyanamide, irrespective of the substance constituting the exposure source. This is supported by experimental results: After stoichiometric correction of test concentrations, toxic effect values of cyanamide and calcium cyanamide are very similar in all standard test organisms. Thus, read-across from cyanamide to calcium cyanamide is justified for aquatic environmental endpoints.
For agricultural applications, calcium cyanamide is formulated as granules (PERLKA) that only slowly dissolve in a soil environment. Exposure of the aquatic environment will be exclusively due to runoff from agricultural fields. As above, cyanamide is the chemical moiety relevant for exposure due to rapid transformation from calcium cyanamide to cyanamide.
(Please note: direct release of the product to surface waters is strictly advised against, thus not a relevant exposure pathway.)

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

43.1 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: lack of mortality and abnormal effects

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

30.6 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: lack of mortality and abnormal effects

Details on results:

There was no mortality below 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The highest concentration causing no mortality was 62.5 mg of a 49% (w/w) aqueous solution of cyanamide/L and the lowest concentration causing 100 % mortality was 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The abnormal effects of loss of equilibrium, fish on the bottom of test chambers and/or quiescence were observed in the 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L test concentrations.

Results with reference substance (positive control):

No positive control

Reported statistics and error estimates:

Not indicated

Sublethal observations / clinical signs:

Mortality of Bluegill sunfish,Lepomis macrochirus, exposed to a 49% (w/w) aqueous solution of cyanamide for 96 hours in an unaerated, static, acute test

Nominal concentrations of the 49% (w/w) aqueous solution of cyanamide (mg/L)	Cumulative mortality (No. dead / No. at test start)
	24 h	48 h	96 h
Water Control	0/10	0/10	0/10
31.2	0/10	0/10	0/10
62.5	0/10	0/10	0/10
125.0	0/10	0/10	10/10
250.0	0/10	0/10	10/10
500.0	5/10	10/10	10/10
1000.0	10/10	10/10	10/10

Acute toxicity (96 h) of Cyanamide toLepomis macrochirus–Summary of endpoints:

Endpoint	Nominal concentration of 49 % (w/w) aqueous solution of Cyanamide
LC50	88.0 mg/L (43.1 mg as/L)
No observed effect concentration (NOEC)	62.5 mg/L (30.6 mg as/L)

Validity criteria fulfilled:

not specified

Conclusions:

The 96-hour LC50 in the Bluegill sunfish was 88.0 mg of a 49% (w/w) aqueous solution of cyanamide/L (equivalent to 43.1 mg as/L, nominal-not measured). The results indicated a 96-hour, NOEC (no observed effect concentration) of 62.5 mg of a 49% (w/w) aqueous solution of cyanamide/L (equivalent to 30.6 mg of the pure as/L), which was based on the lack of mortality and abnormal effects.

Upon dissolution in water calcium cyanamide is fast transformed to hydrogen cyanamide.
Therefore, ecotoxicity in natural aquatic environments can be expressed in terms of cyanamide, irrespective of the substance constituting the exposure source. This is supported by experimental results: After stoichiometric correction of test concentrations, toxic effect values of cyanamide and calcium cyanamide are very similar in all standard test organisms. Thus, read-across from cyanamide to calcium cyanamide is justified for aquatic environmental endpoints.
For agricultural applications, calcium cyanamide is formulated as granules (PERLKA) that only slowly dissolve in a soil environment. Exposure of the aquatic environment will be exclusively due to runoff from agricultural fields. As above, cyanamide is the chemical moiety relevant for exposure due to rapid transformation from calcium cyanamide to cyanamide.
(Please note: direct release of the product to surface waters is strictly advised against, thus not a relevant exposure pathway.)

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Executive summary:

The acute toxicity of LH 21.810 (a 49% (w/w) aqueous solution of cyanamide) to unfed juvenile Bluegill sunfish, Lepomis macrochirus, was determined in a static, 96-hour test. Treatments consisted of a water control and nominal concentrations of 31.2, 62.5, 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Test vessels containing 10 fish each were exposed to each treatment concentration and control. Test solutions were maintained at 22°C. There was no mortality below 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The highest concentration causing no mortality was 62.5 mg of a 49% (w/w) aqueous solution of cyanamide/L and the lowest concentration causing 100 % mortality was 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The abnormal effects of loss of equilibrium, fish on the bottom of test chambers and/or quiescence were observed in the 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L test concentrations. The 96-hour LC50 in the Bluegill sunfish was 88.0 mg of a 49% (w/w) aqueous solution of cyanamide/L (equivalent to 43.1 mg as/L, nominal-not measured). The results indicated a 96-hour, NOEC (no observed effect concentration) of 62.5 mg of a 49% (w/w) aqueous solution of cyanamide/L (equivalent to 30.6 mg of the pure as/L), which was based on the lack of mortality and abnormal effects.

This information is used in a read-across approach in the assessment of the target substance.

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Reference 9

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Justification for type of information:

Upon dissolution in water calcium cyanamide is fast transformed to hydrogen cyanamide.
Therefore, ecotoxicity in natural aquatic environments can be expressed in terms of cyanamide, irrespective of the substance constituting the exposure source. This is supported by experimental results: After stoichiometric correction of test concentrations, toxic effect values of cyanamide and calcium cyanamide are very similar in all standard test organisms. Thus, read-across from cyanamide to calcium cyanamide is justified for aquatic environmental endpoints.
For agricultural applications, calcium cyanamide is formulated as granules (PERLKA) that only slowly dissolve in a soil environment. Exposure of the aquatic environment will be exclusively due to runoff from agricultural fields. As above, cyanamide is the chemical moiety relevant for exposure due to rapid transformation from calcium cyanamide to cyanamide.
(Please note: direct release of the product to surface waters is strictly advised against, thus not a relevant exposure pathway.)

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

80.9 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

29.9 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

behaviour

Remarks on result:

other: The NOEC concentration, based on mean measured concentrations, was estimated to be 61.0 mg of the 49% aqueous solution of cyanamide/L (equivalent to 29.9 mg as/L).

Details on results:

There were no mortality below 250.0 mg of a 49% (w/w) aqueous solution of cyanamide/L and no sublethal effects below 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The highest concentration causing no mortality was 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L and the lowest concentration causing 100 % mortality was 250.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Behavioural/sublethal effects noted during the study included surfacing, erratic swimming, pectoral fins retracted and immobile, fish on bottom of test aquaria, defecating and quiescence. These effects were noted among the fish at test concentration of 125.0, 250.0, and 500.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Therefore, a no-effect concentration - based on mean measured concentrations - was determined to be 61.0 mg of a 49% (w/w) aqueous solution of cyanamide/L.

Results with reference substance (positive control):

No positive control

Reported statistics and error estimates:

Not indicated

Sublethal observations / clinical signs:

No other information

Validity criteria fulfilled:

not specified

Conclusions:

The 96-hour LC50 to Carp was 165.0 mg of the 49% (w/w) aqueous solution of cyanamide/L (equivalent to 80.9 mg as/L). The no-observed effect concentration was estimated to be 61.0 mg of the 49% aqueous solution of cyanamide/L (equivalent to 29.9 mg as/L).

Upon dissolution in water calcium cyanamide is fast transformed to hydrogen cyanamide.
Therefore, ecotoxicity in natural aquatic environments can be expressed in terms of cyanamide, irrespective of the substance constituting the exposure source. This is supported by experimental results: After stoichiometric correction of test concentrations, toxic effect values of cyanamide and calcium cyanamide are very similar in all standard test organisms. Thus, read-across from cyanamide to calcium cyanamide is justified for aquatic environmental endpoints.
For agricultural applications, calcium cyanamide is formulated as granules (PERLKA) that only slowly dissolve in a soil environment. Exposure of the aquatic environment will be exclusively due to runoff from agricultural fields. As above, cyanamide is the chemical moiety relevant for exposure due to rapid transformation from calcium cyanamide to cyanamide.
(Please note: direct release of the product to surface waters is strictly advised against, thus not a relevant exposure pathway.)

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Executive summary:

The acute toxicity of a 49% aqueous solution of cyanamide to unfed juvenile Carp, Cyprinus carpio, was determined in a flow-through, 96-hour test. Treatments consisted of a water control and nominal concentrations of 63.0, 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Test vessels containing 10 fish each were exposed to each treatment concentration and control. Test solutions were maintained at 22°C. The samples of the test medium were analysed using an UV-VIS Spectrophotometer. Mean measured concentrations of the 49% (w/w) aqueous solution of cyanamide were 61.0, 117.0, 232.0, 476.0, and 1040.0 mg/L and ranged from 93 to 104 % of nominal concentrations. In the test medium the test item was sufficiently stable during the test period of 96 hours. There were no mortality below 250.0 mg of a 49% (w/w) aqueous solution of cyanamide/L and no sublethal effects below 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The highest concentration causing no mortality was 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L and the lowest concentration causing 100 % mortality was 250.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Behavioural/sublethal effects noted during the study included surfacing, erratic swimming, pectoral fins retracted and immobile, fish on bottom of test aquaria, defecating and quiescence. These effects were noted among the fish at test concentration of 125.0, 250.0, and 500.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Therefore, a no-effect concentration - based on mean measured concentrations - was determined to be 61.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The 96-hour LC50 to Carp was 165.0 mg of the 49% (w/w) aqueous solution of cyanamide/L (equivalent to 80.9 mg as/L). The no-observed effect concentration was estimated to be 61.0 mg of the 49% aqueous solution of cyanamide/L (equivalent to 29.9 mg as/L).

This information is used in a read-across approach in the assessment of the target substance.

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Description of key information

The LC50 (96 h) of Calcium cyanamide, technical grade (Kalkstickstoff) in zebra fish was determined to be 140 mg/L based on nominal concentration. The NOEL was determined to be 100 mg/L. The calcium cyanamide, technical grade samples used in the test contains 69.3 % of calcium cyanamide. Thus, re-calculation to 100 % calcium cyanamide results in the following effects values:

-       LC50 = 97.02 mg as/L

-       NOEL = 69.3 mg as/L

In addition, four short-term toxicity tests were performed with the read-across substance cyanamide:

The short-term toxicity to fish was examined in four available studies with a 49% (w/w) solution of cyanamide. Most of the studies were conducted in a 96-hour static test with different species of unfed freshwater fish. A LC50 of 43.1 as mg/L and a NOEC of 30.6 mg as/L were obtained in the key study with Bluegill sunfish (lepomis macrochirus) fish.

The LC50 of 43.1 mg cyanamide/L corresponds to a concentration of 82.1 mg calcium cyanamide/L.

The lowest available LC50 value of 43.1 mg cyanamide /L for Bluegill sunfish is carried forward as key value for chemical safety assessment.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

43.1 mg/L

Additional information

Upon dissolution in water calcium cyanamide is fast transformed to hydrogen cyanamide.

Therefore, ecotoxicity in natural aquatic environments can be expressed in terms of cyanamide, irrespective of the substance constituting the exposure source. This is supported by experimental results: After stoichiometric correction of test concentrations, toxic effect values of cyanamide and calcium cyanamide are very similar in all standard test organisms. Thus, read-across from cyanamide to calcium cyanamide is justified for aquatic environmental endpoints.

For agricultural applications, calcium cyanamide is formulated as granules (PERLKA) that only slowly degrade in a soil environment. Exposure of the aquatic environment will be exclusively due to runoff from agricultural fields. As above, cyanamide is the chemical moiety relevant for exposure due to the rapid transformation from calcium cyanamide to cyanamide.

(Please note: direct release of the product to surface waters is strictly advised against, thus not a relevant exposure pathway.)

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

In a 96-h acute toxicity study, Zebrafish (Danio rerio) were exposed to calcium cyanamide, technical grade (Kalkstickstoff) at nominal concentrations of 0, 25.0, 51.3, 101.0, 200.4, 401.1 mg/L under semi-static conditions (media exchange after 48 h). Calcium cyanamide is a substance with impurities and is of limited solubility in aqueous media. The sample tested contains 69.3 % calcium cyanamide. Therefore, the fish were exposed to separate preparations of different loading rates of water accommodated fractions (WAFs). Mean nominal loading rates of 25.0, 51.3, 101.0, 200.4, and 401.1 mg per litre were obtained by stirring the respective amount of test substance in dilution water for 60 minutes in the dark at the start of the test as well as 48 hours thereafter. Afterwards undissolved particles were removed by filtration (0.45 μm) and the clear filtrate was used for the test. The dilution water was local tap water which was mixed 1+1 with deionised water to achieve the appropriate water hardness as required by the guideline. Dilution water was also used for the negative control group. Analytical data supported the use of nominal concentrations for the derivation of reference figures.

All fish of group E (401.1 mg/L) died within the first 2 hours of exposure. The fish in group D (200.4 mg/L) showed decreased mobility after 2 hours of exposure, after 24 hours the first fish died. After 48 hours of exposure the remaining fish in group D showed loss of equilibrium and bleedings around the mouth and the chest, and 3 further dead fish were recorded. The remaining fish in group D were dead 24 hours later. All fish in the other test groups as well as in the control group were inconspicuous in appearance and behaviour throughout the study.

The 96-h LC50 was 140 mg test material/L. The NOEC value, based on mortality was 100 mg test material/L.

In addition, available short-term toxicity studies with the read-across partner cyanamide were considered:

The acute toxicity of cyanamide (49% (w/w) aqueous solution of cyanamide) to fish was examined in four available studies which were conducted in a similar way. The four studies were performed with different fish species, unfed in a static (except for Bowman´s study), 96-hour test. Altogether the key study and the supporting studies exhibited a low toxicity to fish.

In the key study (McAllistar, 1985, Doc.No., 821-002) Bluegill sunfish (Lepomis macrochirus) were treated with nominal concentrations of 31.2, 62.5, 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. Test vessels containing 10 fish each were exposed to each treatment concentration and control. There was no mortality below 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The highest concentration causing no mortality was 62.5 mg of a 49% (w/w) aqueous solution of cyanamide/L and the lowest concentration causing 100 % mortality was 125.0 mg of a 49% (w/w) aqueous solution of cyanamide/L. The abnormal effects of loss of equilibrium, fish on the bottom of test chambers and/or quiescence were observed in the 125.0, 250.0, 500.0, and 1000.0 mg of a 49% (w/w) aqueous solution of cyanamide/L test concentrations. The 96-hour LC50 in the Bluegill sunfish was 88.0 mg of a 49% (w/w) aqueous solution of cyanamide/L (equivalent to 43.1 mg as/L, nominal-not measured). The results indicated a 96-hour, NOEC (no observed effect concentration) of 62.5 mg of a 49% (w/w) aqueous solution of cyanamide/L (equivalent to 30.6 mg of the pure as/L), which was based on the lack of mortality and abnormal effects.

In another study of McAllistar (1985, Doc.No., 821-001) which was also conducted with Bluegill sunfish (Lepomis macrochirus) a LC50 of 88.2 mg as/L of cyanamide and a similar NOEC to the one of the key study: 30.6 as mg/L cyanamide were obtained.

A study conducted in a flow-through conditions with Carp (Cyprinus carpius) fish (Bowman, 1990, Doc. No., 821-003) obtained a LC50 of 80.9 as mg/L and a NOEC of 29.9 as mg/L of cyanamide.

In a study conducted with Rainbow trout (Oncorrhynchus mykiss) fish similar results to the key study were obtained: LC50 of 45.6 as mg/L and a NOEC of 31.8 as mg/L (Barrows, 1985).