Monalazone disodium

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

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

Adequacy of study:

supporting study

Study period:

2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Justification for type of information:

Read-across justification is provided in Appendix 3 of the CSR.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

ISO 8692 (Water Quality - Fresh Water Algal Growth Inhibition Test with Scenedesmus subspicatus and Selenastrum capricornutum)

Deviations:

not specified

GLP compliance:

not specified

Specific details on test material used for the study:

Name of test material (as cited in study report): Methylparaben

Analytical monitoring:

not specified

Details on sampling:

no data

Vehicle:

no

Details on test solutions:

no data

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

no data

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

no data

Hardness:

no data

Test temperature:

no data

pH:

no data

Dissolved oxygen:

no data

Salinity:

no data

Nominal and measured concentrations:

Nominal concentrations: 2, 5, 10, 20, 50, 100, 200 mg/L measured concentrations: no data

Details on test conditions:

TEST SYSTEM
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

TEST MEDIUM
Exponentially growing batch cultures of algae were exposed to a serial dilution of the test substance. The test was incubated on a shaking table under constant temperature and light.

EFFECT PARAMETERS MEASURED:
The cell densities were determined by fluoremetric measurement after 24, 48, and 72 hours of exposure. The inhibition of growth at each test concentration was determined as the average growth rate in per cent of the control growth rate.

The concentrations, which inhibited the growth rate 10 and 50%, were calculated by use of a computer program ‘Toxedo’ (VKI 1992). The highest concentration at which no significant effect was observed (No Observed Effect Concentration, NOEC), was determined by Dunnett’s procedure (US-EPA 1989).

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

31 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CL: 29-32 mg/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

91 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CL: 90-93 mg/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 200 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: -

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

20 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: -

Statistical parameters calculated from continuous responses based on continuous mean.

Test type : Growth Inhibition Test.

6 doses and 13 responses have been used during calculations.

Concentration	Growth	Inhibition
in mg/L		[%]
Control values
Control 1	2.102	-
Control 2	2.094	-
Control 3	2.101	-
Control 4	2.123	-
Control 5	2.118	-
Control 6	2.102	-
Control mean	2.107	0
Experimental data
2	2.046	2.9
2	2.129	0.0
2	2.086	1.0
5	2.129	0.0
5	2.109	0.0
5	2.093	0.6
10	2.151	0.0
10	2.132	0.0
10	2.029	3.7
20	2.108	0.0
20	2.114	0.0
20	2.137	0.0
50	1.836	12.8
50	1.820	13.6
50	1.779	15.6
100	0.917	56.5
100	0.908	56.9
100	0.908	56.9
200	0.337	84.0
200	0.337	84.0
200	0.341	83.8

Validity criteria fulfilled:

not specified

Conclusions:

The toxicity to aquatic algae (Pseudokirchneriella subcapitata) was determined in a study based on a ISO guideline and the EC50 after 72 hours was determined to be 91 mg/L.

Executive summary:

The toxicity to aquatic algae (Pseudokirchneriella subcapitata) was determined in a study based on a ISO guideline and the EC50 after 72 hours was determined to be 91 mg/L.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

The calculation was using the scientific acceptable software program as recommended in REACH Guideline R.6 under REACH Regulation (EC) No 1907/2006.

SMILES (used for QSAR prediction): C(=O)(O)c1ccc(S(=O)(O)=NCl)cc1

ID of substance (used for QSAR prediction)
EC Number 262-810-2 Registry Number 61477-95-0 PubChem CID
Chemical Name monalazone disodium
Molecular Formula C7 H6 CL1 N1 O4 S1 Molecular weight (g/mole) 235.64

Qualifier:

according to guideline

Guideline:

other: REACH Guidance on QSARs R.6

Deviations:

not specified

GLP compliance:

no

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

342.051 mg/L

Nominal / measured:

estimated

Conc. based on:

other: Battery

Basis for effect:

not specified

Remarks on result:

other: Domain: IN

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

109.126 mg/L

Nominal / measured:

estimated

Conc. based on:

other: Leadscope

Basis for effect:

not specified

Remarks on result:

other: Domain: IN

Reference 3

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

The calculation was using the scientific acceptable software program as recommended in REACH Guideline R.6 under REACH Regulation (EC) No 1907/2006.

SMILES (used for QSAR prediction): C(=O)(O)c1ccc(S(=O)(O)=NCl)cc1

ID of substance (used for QSAR prediction)
EC Number 262-810-2 Registry Number 61477-95-0 PubChem CID
Chemical Name monalazone disodium
Molecular Formula C7 H6 CL1 N1 O4 S1 Molecular weight (g/mole) 235.64

Qualifier:

according to guideline

Guideline:

other: REACH Guidance on QSARs R.6

Deviations:

not specified

GLP compliance:

not specified

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

303 mg/L

Nominal / measured:

estimated

Conc. based on:

other: ECOSAR Classes: Amides -acid

Basis for effect:

growth rate

Remarks on result:

other: Most Toxic Class: Amides -acid. Max. Log Kow for Most Toxic Class: >8

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

1 512.181 mg/L

Nominal / measured:

estimated

Conc. based on:

not specified

Basis for effect:

not specified

Remarks on result:

other: Neutral Organic SAR

Description of key information

Testing to aquatic algae and cyanobacteria was considered not necessary as alternatives to testing were available and they demonstrated to be sufficient to fulfil the requirement of Annex VII 9.1.2 on Growth inhibition study aquatic plants. Therefore, the general rules for adaption 1.2, 1,3 and 1.5 of Annex XI of REACH regulation were applied. The results obtained from QSARs models indicated the absence of hazardous to the aquatic environment and the testing with the registered substance was considered not reasonable. Furthermore, read across data from a similar substance was used as supporting information.

The following data has been taken into account for the hazard assessment:

-72h EC50: 303 mg/L (ECOSAR v1.11)

-72h EC50: 109.12 mg/L (Danish QSAR Database)

-72h EC50: 91 mg/l: NOEC: 20 mg/L: EC10: 31 mg/L (read across)

Key value for chemical safety assessment

EC50 for freshwater algae:

109 mg/L

EC50 for marine water algae:

109 mg/L

EC10 or NOEC for freshwater algae:

109 mg/L

EC10 or NOEC for marine water algae:

109 mg/L