3,4-dichlorophenyl isocyanate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Guideline study, basic data given, peer reviewed in BUA Report

Justification for type of information:

Due to insufficient reporting of the experimental details, this study was rated with a Klimisch score of 4 (‘not assignable’). As none of the available studies can serve as a key study with a sufficiently detailed reporting justifying a Klimisch score of 1 or 2 for the given endpoint, several independent sources were used in a weight of evidence approach. ‘Using weight of evidence implies that no single study of sufficient quality and reliability exists, and that information from several independent sources is required to be able to reach a conclusion on a particular property of the substance.' (guidance document How to prepare registration and PPORD dossiers, p. 87)
For further details on the justification for the use of data on the hydrolysis product 3,4-dichloroaniline please refer to chapter 13.2.

Principles of method if other than guideline:

Method: other: DIN 38412, Teil 11

GLP compliance:

not specified

Specific details on test material used for the study:

The hydrolysis of 3,4-dichlorophenyl isocyanate is expected to occur faster than within 12 h (Please refer to the expert statement in section 13.) Thus, it is technically not feasible to conduct toxicity tests towards the aquatic species with the test item 3,4-dichlorophenyl isocyanate, as the hydrolysis will take place fully, well before the regular test medium is exchanged. The short-term toxicity towards aquatic invertebrates and toxicity towards algae was therefore investigated using the hydrolysis product 3,4-dichloronaniline.

Analytical monitoring:

not specified

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

1.3 mg/L

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

4.3 mg/L

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

10 mg/L

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

0.63 mg/L

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.8 mg/L

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

10 mg/L

Validity criteria fulfilled:

not specified

Conclusions:

For Daphnia magna, an EC50 of 2.8 mg/l after 48 h of exposure was obtained for 3,4-dichloroaniline (the main hydrolysis product of 3,4-dichlorophenyl isocyanate).

Executive summary:

Kühn, 1989

The acute toxicity of 3,4-dichloroaniline, the main hydrolysis product of 3,4-dichlorophenyl isocyanate, was assessed (static, freshwater test following DIN 38412, Teil 11). For Daphnia magna, an EC50 of 2.8 mg/l after 48 h of exposure was obtained.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Only basic data given, peer reviewed in BUA report.

Justification for type of information:

Due to insufficient reporting of the experimental details, this study was rated with a Klimisch score of 4 (‘not assignable’). As none of the available studies can serve as a key study with a sufficiently detailed reporting justifying a Klimisch score of 1 or 2 for the given endpoint, several independent sources were used in a weight of evidence approach. ‘Using weight of evidence implies that no single study of sufficient quality and reliability exists, and that information from several independent sources is required to be able to reach a conclusion on a particular property of the substance.' (guidance document How to prepare registration and PPORD dossiers, p. 87)
For further details on the justification for the use of data on the hydrolysis product 3,4-dichloroaniline please refer to chapter 13.2.

Qualifier:

no guideline available

Principles of method if other than guideline:

Method: Semistatic Test system

GLP compliance:

no

Specific details on test material used for the study:

The hydrolysis of 3,4-dichlorophenyl isocyanate is expected to occur faster than within 12 h (Please refer to the expert statement in section 13.) Thus, it is technically not feasible to conduct toxicity tests towards the aquatic species with the test item 3,4-dichlorophenyl isocyanate, as the hydrolysis will take place fully, well before the regular test medium is exchanged. The short-term toxicity towards aquatic invertebrates and toxicity towards algae was therefore investigated using the hydrolysis product 3,4-dichloronaniline.

Analytical monitoring:

not specified

Vehicle:

yes

Details on test solutions:

- Chemical name of vehicle: Ethanol

Test organisms (species):

Daphnia magna

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 d

Test temperature:

18- 22 °C

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.12 mg/L

Conc. based on:

test mat.

Basis for effect:

mortality

Validity criteria fulfilled:

not specified

Conclusions:

For Daphnia magna, a LC50 of 0.12 mg/l after 96 h of exposure was obtained for 3,4-dichloroaniline (the main hydrolysis product of 3,4-dichlorophenyl isocyanate).

Executive summary:

Van der Meer, 1988

The acute toxicity of 3,4-dichloroaniline, the main hydrolysis product of 3,4-dichlorophenyl isocyanate, was assessed (semi-static, freshwater test). For Daphnia magna, a LC50 of 0.12 mg/l after 96 h of exposure was obtained.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Peer reviewed data, cited in EU Risk assessment.

Justification for type of information:

Due to insufficient reporting of the experimental details, this study was rated with a Klimisch score of 4 (‘not assignable’). As none of the available studies can serve as a key study with a sufficiently detailed reporting justifying a Klimisch score of 1 or 2 for the given endpoint, several independent sources were used in a weight of evidence approach. ‘Using weight of evidence implies that no single study of sufficient quality and reliability exists, and that information from several independent sources is required to be able to reach a conclusion on a particular property of the substance.' (guidance document How to prepare registration and PPORD dossiers, p. 87)
For further details on the justification for the use of data on the hydrolysis product 3,4-dichloroaniline please refer to chapter 13.2.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

no

Specific details on test material used for the study:

The hydrolysis of 3,4-dichlorophenyl isocyanate is expected to occur faster than within 12 h (Please refer to the expert statement in section 13.) Thus, it is technically not feasible to conduct toxicity tests towards the aquatic species with the test item 3,4-dichlorophenyl isocyanate, as the hydrolysis will take place fully, well before the regular test medium is exchanged. The short-term toxicity towards aquatic invertebrates and toxicity towards algae was therefore investigated using the hydrolysis product 3,4-dichloronaniline.

Analytical monitoring:

not specified

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Aliquotes of stock solutions of DCA in analytical grade acetone were added to give an approximately logarithmic series of concentrations.
The concentrations of acetone was adjusted to 0.5 mg/L.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: Culture derived from a strain optained from the Institute National de Recherche Chimique Applique, France
- Age at study initiation: < 24 h

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Details on test conditions:

TEST SYSTEM
- Test vessel: 150 ml glass beakers, 100 ml fill volume
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3
- No. of vessels per vehicle control (replicates): 3



TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: filtered chlorinated tap water.

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.29 mg/L

Validity criteria fulfilled:

not specified

Conclusions:

For Daphnia magna, an EC50 of 0.29 mg/l after 48 h of exposure was obtained for 3,4-dichloroaniline (the main hydrolysis product of 3,4-dichlorophenyl isocyanate).

Executive summary:

Crossland, 1985

The acute toxicity of 3,4-dichloroaniline, the main hydrolysis product of 3,4-dichlorophenyl isocyanate, was assessed (static, freshwater test similar to OECD TG 202). For Daphnia magna, an EC50 of 0.29 mg/l after 48 h of exposure was obtained.

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Test procedure in accordance with national standard methods with acceptable restrictions. Peer-reviewed data from EU-RAR of the hydrolysis product 3,4-dichloroaniline.

Justification for type of information:

Due to insufficient reporting of the experimental details, this study was rated with a Klimisch score of 4 (‘not assignable’). As none of the available studies can serve as a key study with a sufficiently detailed reporting justifying a Klimisch score of 1 or 2 for the given endpoint, several independent sources were used in a weight of evidence approach. ‘Using weight of evidence implies that no single study of sufficient quality and reliability exists, and that information from several independent sources is required to be able to reach a conclusion on a particular property of the substance.' (guidance document How to prepare registration and PPORD dossiers, p. 87)
For further details on the justification for the use of data on the hydrolysis product 3,4-dichloroaniline please refer to chapter 13.2.

Principles of method if other than guideline:

national standard method: described in handbook "Degradability, Ecotoxicity and Bioaccumulation; The determination of the possible effects of chemicals and wastes on the aquatic environment (TNO, 1980)"

GLP compliance:

no

Specific details on test material used for the study:

The hydrolysis of 3,4-dichlorophenyl isocyanate is expected to occur faster than within 12 h (Please refer to the expert statement in section 13.) Thus, it is technically not feasible to conduct toxicity tests towards the aquatic species with the test item 3,4-dichlorophenyl isocyanate, as the hydrolysis will take place fully, well before the regular test medium is exchanged. The short-term toxicity towards aquatic invertebrates and toxicity towards algae was therefore investigated using the hydrolysis product 3,4-dichloronaniline.

Analytical monitoring:

yes

Details on sampling:

at test start

Vehicle:

not specified

Test organisms (species):

Daphnia magna

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

hard

Test temperature:

19°C

pH:

about 8

Dissolved oxygen:

never less than 70 % of the saturation value

Key result

Duration:

48 h

Dose descriptor:

LC50

Remarks:

1 mm, larvae

Effect conc.:

0.23 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

96 h

Dose descriptor:

LC50

Remarks:

1 mm, larvae

Effect conc.:

0.16 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

7 d

Dose descriptor:

LC50

Remarks:

1 mm, larvae

Effect conc.:

0.12 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

LC50

Remarks:

3 mm, adults

Effect conc.:

12 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

96 h

Dose descriptor:

LC50

Remarks:

3 mm, adults

Effect conc.:

1 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

7 d

Dose descriptor:

LC50

Remarks:

3 mm, adults

Effect conc.:

< 0.58 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

-the concentration of the test compound in the water was measured by chemical analysis during the test and was at least 70% of the nominal value

Validity criteria fulfilled:

not specified

Conclusions:

For Daphnia magna, a LC50 of 0.23 mg/l (larvae, 1 mm) after 48 h of exposure was obtained for 3,4-dichloroaniline (the main hydrolysis product of 3,4 -dichlorophenyl isocyanate).

Executive summary:

Adema, 1981

The acute toxicity of 3,4-dichloroaniline, the main hydrolysis product of 3,4-dichlorophenyl isocyanate, was assessed following a national standard method for the determination of toxicity to invertebrates. For Daphnia magna, a LC50 of 0.23 mg/l (larvae, 1 mm) after 48 h of exposure was obtained.

Description of key information

For 3,4-dichlorophenyl isocyanate no short-term tests on toxicity to invertebrates are available. Therefore, the short-term toxicity test of the main hydrolysis product 3,4-dichloroaniline with the lowest value is used to draw a conclusion on toxicity to invertebrates for the parent compound. For further details please refer to chapter 13.2.

In order to fulfill the data requirements a weight of evidence (WoE) approach (REACh Regulation (EC) No. 1907/2006, Annex XI Section 1.2) was chosen. This approach is a possible adaptation to the standard information requirements which ‘should be undertaken to maximise the use of existing data and minimise the commissioning of new in vivo testing’ (ECHA Guidance R.7a, 2017, p. 364). The WoE approach serves to reduce or avoid animal testing, which should only be performed as last resort (REACh, article 25). The individual study reports were conducted in accordance with standardized guidelines. The study reports nevertheless show some deficiencies with respect to the comprehensiveness of the presented experimental details. Therefore, a reliability of 1 or 2 and thus adequacy as key study was not assignable for any of the individual studies. Consequently, the studies were assigned a Klimisch score of 4 (according to guidance document R.4, ‘not assignable: studies or data […] which do not give sufficient experimental details […]). Collectively, these experimental studies can be used to conclude on this endpoint and to satisfy the information requirement.

Adema, 1981

The acute toxicity of 3,4-dichloroaniline was assessed following a national standard method for the determination of toxicity to invertebrates. For Daphnia magna, a LC50 of 0.23 mg/l (larvae, 1 mm) after 48 h of exposure was obtained. 

Van der Meer, 1988

The acute toxicity of 3,4-dichloroaniline, the main hydrolysis product of 3,4-dichlorophenyl isocyanate, was assessed (semi-static, freshwater test). For Daphnia magna, a LC50 of 0.12 mg/l after 96 h of exposure was obtained.

Kühn, 1989

The acute toxicity of 3,4-dichloroaniline, the main hydrolysis product of 3,4-dichlorophenyl isocyanate, was assessed (static, freshwater test following DIN 38412, Teil 11). For Daphnia magna, an EC50 of 2.8 mg/l after 48 h of exposure was obtained.

Crossland, 1985

The acute toxicity of 3,4-dichloroaniline, the main hydrolysis product of 3,4-dichlorophenyl isocyanate, was assessed (static, freshwater test similar to OECD TG 202). For Daphnia magna, an EC50 of 0.29 mg/l after 48 h of exposure was obtained.

Conclusion

The EC50/LC50 values obtained from these studies are in the same order of magnitude.

48h-EC50/LC50: 0.23 - 2.8 mg/l

96-h LC50: 0.12 mg/l

The most conservative EC50 of 0.23 mg/l (Adema, 1981) obtained for the standard exposure time of 48h as outlined in OECD 202 was chosen as key value for chemical safety assessment.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

LC50

Effect concentration:

0.23 mg/L