Cyanamide

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Details on sampling:

No sampling

Vehicle:

no

Details on preparation and application of test substrate:

- In the test a mixture AHL and 22 % (w/w) of the cyanamide solution ”SKW Cyanamid L500” was used
- The study is an artificial soil test

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

Not indicated

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

14 d

Test temperature:

Not indicated

pH:

Not indicated

Moisture:

Not indicated

Details on test conditions:

Four replicates of 10 clitellated adult earthworms were each exposed to nominal concentrations of 62.5, 125, 250, 500 and 1000 mg SKW Cyanamid L500 + AHL/kg dry soil weight (ppm in dry soil). Controls were replicated 4 times, with 10 earthworms in each replicate. The toxic reference standard was tested at 5 rates in a separate study. Worms were assessed for mortality and sublethal effects after 7 and 14 days of exposure and earthworm body weights were assessed at day 0 and day 14.

Nominal and measured concentrations:

Nominal concentrations of 62.5, 125, 250, 500 and 1000 mg SKW Cyanamid L500 + AHL/kg dry soil weight (ppm in dry soil).

Reference substance (positive control):

yes

Key result

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

> 111.3 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: corresponding to 1000 mg/kg soil dw of test material

Duration:

14 d

Dose descriptor:

LOEC

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: weight loss

Key result

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

500 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

behaviour

Details on results:

No significant sublethal behavioural effects were observed up to a rate of 500 mg SKW Cyanamid L500 + AHL/kg dry soil weight. At an application rate of 1000 mg SKW Cyanamid L500 + AHL /kg dry soil weight, a significant cumulative weight loss of -69.7 % was observed. The LC50 for the toxic reference standard was 21.1 mg/kg soil dry weight; this is within accepted limits indicating the validity of this test.

Results with reference substance (positive control):

The LC50 for the toxic reference standard was 21.1 mg/kg soil dry weight; this is within accepted limits indicating the validity of this test.

Reported statistics and error estimates:

The test group results were significantly different compared to the control by the Dunnett test, α=0.05

Acute toxicity of SKW Cyanamid L500 + AHL to earthworms:

Treatment	Cumulative Mortality (%)^a		Cumulative Weight Loss (%)^b
(mg SKW Cyanamid L500 + AHL/kg dry soil)	7 days	14 days	14 days
0	0	0	-
62.5	0	0	3.4
125	0	0	33.1
250	0	0	26.2
500	0	2.5	12.4
1000	0	0	-69.7*

 

Validity criteria fulfilled:

yes

Conclusions:

The acute earthworm LC50 of SKW Cyanamid L500 + AHL was determined to be > 111.3 mg/kg dry soil (active substance cyanamide), the highest rate tested.

Executive summary:

The acute toxicity of SKW Cyanamid L500 + AHL to earthworms, Eisenia fetida, was determined in a 14-day soil exposure laboratory study. Four replicates of 10 clitellated adult earthworms were each exposed to nominal concentrations of 62.5, 125, 250, 500 and 1000 mg SKW Cyanamid L500 + AHL/kg dry soil weight (ppm in dry soil). Controls were replicated 4 times, with 10 earthworms in each replicate. The toxic reference standard was tested at 5 rates in a separate study. Worms were assessed for mortality and sublethal effects after 7 and 14 days of exposure and earthworm body weights were assessed at day 0 and day 14. No significant sublethal behavioural effects were observed up to a rate of 500 mg SKW Cyanamid L500 + AHL/kg dry soil weight. At an application rate of 1000 mg SKW Cyanamid L500 + AHL /kg dry soil weight, a significant cumulative weight loss of 69.7 % was observed. The LC50 for the toxic reference standard was 21.1 mg/kg soil dry weight; this is within accepted limits indicating the validity of this test.

 

It can be concluded that the acute earthworm LC50 of SKW Cyanamid L500 + AHL was determined to be > 111.3 mg/kg dry soil (active substance cyanamide), the highest rate tested.

Description of key information

The acute toxicity effects of cyanamide on earthworms were tested in a 14-day laboratory study. The LC50 observed after 14 days of incubation was > 111.3 mg/kg dry soil (active substance cyanamide), the highest rate tested. The long-term toxicity effects of cyanamide on earthworms were tested in a study according to OECD guideline 222 (Earthworm Reproduction Test). The NOEC for biomass (28 d), mortality (28 d) and reproduction (56 d) was determined to be ≥ 1.05 mg a.s./kg soil (dw), the highest dos tested. This value was not considered relevant for chemical safety assessment, for justification please refer to IUCLID section 6.3 (Enpoint summary for terrestrial toxicity).

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil macroorganisms:

111.3 mg/kg soil dw

Additional information

The acute toxicity of cyanamide (SKW Cyanamid L500 + AHL (synonymous to urea ammonium nitrate)) to earthworms, Eisenia fetida, was determined in a 14-day soil exposure laboratory study. Four replicates of 10 clitellated adult earthworms were each exposed to nominal concentrations of 62.5, 125, 250, 500 and 1000 mg SKW Cyanamid L500 + AHL/kg dry soil weight (ppm in dry soil). Controls were replicated 4 times, with 10 earthworms in each replicate. The toxic reference standard was tested at 5 rates in a separate study. Worms were assessed for mortality and sublethal effects after 7 and 14 days of exposure and earthworm body weights were assessed at day 0 and day 14. No significant sublethal behavioural effects were observed up to a rate of 500 mg SKW Cyanamid L500 + AHL/kg dry soil weight. At an application rate of 1000 mg SKW Cyanamid L500 + AHL /kg dry soil weight, a significant cumulative weight loss of 69.7 % was observed. It can be concluded that the LC50 for the toxic reference standard was 21.1 mg/kg soil dry weight; this is within accepted limits indicating the validity of this test. It can be concluded that the acute earthworm LC50 of SKW Cyanamid L500 + AHL was determined to be > 111.3 mg/kg dry soil (active substance cyanamide), the highest rate tested.

 

The long-term toxicity effects of cyanamide (50 % aqueous solution) on earthworms were tested in a study according to OECD guideline 222 (Earthworm Reproduction Test). The purpose of this study was to determine a NOEC/LOEC and if possible, an EC10, EC20 and EC50 value for reproduction (56 days after application) and a NOEC/LOEC value for mortality and the biomass development (28 days after application) of the earthworm Eisenia fetida (Lumbricidae) using a standard LUFA 2.2 soil. The test item was mixed with the substrate. The earthworm Eisenia fetida (Lumbricidae) was chosen as a representative of the soil fauna. Biomass, mortality and reproduction were not affected by the treatment. Therefore, the NOEC for biomass (28 d), mortality (28 d) and reproduction (56 d) was determined to be ≥ 1.05 mg a.s./kg soil (dw), the highest dos tested. This value was not considered reliable due to significant methodological deficiencies and thus regarded not relevant for chemical safety assessment (please also refer to IUCLID section 6.3 (Enpoint summary for terrestrial toxicity).