1,2,4-trichlorobenzene

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:

documentation insufficient for assessment

Remarks:

Original reference not available.

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)

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

04.04.1984

Deviations:

not specified

GLP compliance:

not specified

Analytical monitoring:

no

Test organisms (species):

Daphnia magna

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

7.69 mg/L

Executive summary:

Oikari (1992)

The toxicity of the test substance to Daphnia magna was assessed after an exposure time of 48h.

LC50 (48h): 7.69 mg/L

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1995

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

GLP-Guideline study. Basic data given.

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)

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

not specified

GLP compliance:

yes

Test organisms (species):

Daphnia magna

Water media type:

freshwater

Total exposure duration:

48 h

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1.4 mg/L

Basis for effect:

mobility

Validity criteria fulfilled:

not specified

Remarks:

The documentation is not sufficient enough to determine the validity criteria.

Conclusions:

The found EC50 after 96 hours was 1.4 mg/l.

Executive summary:

National Institute of Technology and Evaluation, Japan (2009).

 

In 1995 the National Institute of Technology and Evaluation (NITE) of Japan tested the acute toxicity of 1,2,4-Trichlorobenzene to Daphnia magna. The test was conducted according to OECD TG 202 and OECD-GLP standard and is considered to be valid. The found EC₅₀ after 96 hours was 1.4 mg/l.

Description of key information

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.

 

National Institute of Technology and Evaluation, Japan (2009)

In 1995 the National Institute of Technology and Evaluation (NITE) of Japan tested the acute toxicity of 1,2,4-Trichlorobenzene to Daphnia magna. The test was conducted according to OECD TG 202 and OECD-GLP standard and is considered to be valid. The found EC₅₀ after 96 hours was 1.4 mg/l.

 

Oikari (1992)

The toxicity of the test substance to Daphnia magna was assessed after an exposure time of 48h.

LC₅₀ (48h): 7.69 mg/L.

 

EU Risk Assessment (2003):

The reported EC₅₀ values assessed in different test species dervied after 48-96h range between 0.45 mg/l (Clark et al., 1987) and 3.39 mg/l (Holcombe et al., 1987).

Several studies have been performed. Most studies have not considered the problems with evaporation and in most studies concentrations have not been measured during the study. Results from such studies are not regarded valid and not presented below.

In a study by Hermens et al. (1984), the acute toxicity to Daphnia magna was an EC₅₀-48h of 2.68 mg/l. The results are not corrected for the measured concentrations. Assuming the average concentration to be the same as in an identical experiment by Hermens et al. (1985), the acute EC₅₀-48h in this study was 1.55 mg/l. The geometric mean of the accepted studies on Daphnia magna is an EC₅₀ (48 h) of 2.1 mg/l.

 

BUA report (1987):

The reported EC₅₀ values for 24 h lasting tests differ in a wide range between 1.2 mg/l (Knie et al., 1983) and 110 mg/l (LeBlanc, 1980). In contrast EC₅₀ values for 48 h lasting tests are closer, ranging between 1.7 mg/l (Richter et al., 1983) and 50.2 mg/l (Buikema and Benfield, 1980). 

 

Conclusion

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

48h-EC₅₀: 1.4 - 50.2 mg/L

The most conservative EC₅₀ of 1.4 mg/l (NITE, 2009) was obtained after 48h.

 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

1.4 mg/L