1,2-dichlorobenzene

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

Acceptable, well documented publication which meets basic scientific principles

Principles of method if other than guideline:

The test was a flow-through test using a proportional diluter system, in which there were five toxicant concentrations plus a control all in duplicate. The diluter cycled every 10-16 minutes, providing from 6.8 to 10.6 volume additions per day. Ten Rainbow trout (Salmo gairdneri, now Oncorhynchus mykiss) were tested per chamber for 6 days. Fingerlings were acclimated and maintained in Lake Superior water at 12 °C until used in testing. Water quality parameter (temperature, dissolved oxygen, hardness, alkalinity, acidity and pH) were monitored and the toxicant concentrations were measured daily. Observations on fish were made daily (except for day 5) for mortalities and other gross behavioural effects.

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

144 h

Duration:

22 h

Dose descriptor:

LC50

Effect conc.:

1.65 mg/L

Nominal / measured:

meas. (not specified)

Basis for effect:

mortality (fish)

Remarks on result:

other: 1.49 - 1.84

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

1.58 mg/L

Nominal / measured:

meas. (not specified)

Basis for effect:

mortality (fish)

Remarks on result:

other: 1.44 - 1.73

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

1.58 mg/L

Nominal / measured:

meas. (not specified)

Basis for effect:

mortality (fish)

Remarks on result:

other: 1.44 - 1.73

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.58 mg/L

Nominal / measured:

meas. (not specified)

Basis for effect:

mortality (fish)

Remarks on result:

other: 1.44 - 1.73

Duration:

144 h

Dose descriptor:

LC50

Effect conc.:

1.54 mg/L

Nominal / measured:

meas. (not specified)

Basis for effect:

mortality (fish)

Remarks on result:

other: 1.42 - 1.68

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.52 - 1.58 mg/L

Basis for effect:

mortality (fish)

Remarks on result:

other: Call et al (1979)

Conclusions:

The acute toxicity of 1,2 -dichlorobenzene to Rainbow trout (Salmo gairdneri, now Oncorhynchus mykiss) was investigated under flow-through conditions for 144 h and resulted in LC50 values of 1.58 mg/L (measured concentration) after 96 h of exposure and of 1.54 mg/L after 144 h.

Executive summary:

Call et al (1979,1983).

The acute toxicity of 1,2 -dichlorobenzene to Rainbow trout (Salmo gairdneri, now Oncorhynchus mykiss) was investigated under flow-through conditions for 144 h and resulted in LC50 values of 1.58 mg/L (measured concentration) after 96 h of exposure and of 1.54 mg/L after 144 h.

In a further publication (WHO, 2004), the LC50 (96 h) for the Rainbow trout determined by Call et al (1979) was reported to be in the range of 1.52 and 1.58 mg/L. This cited publication is not available and the reliablity is thus not assignable. As the authors of both publications are the same (Call et al) it is be assumed that the test methods are identical. Therefore, the lowest LC50 of 1.52 mg/L is considered as worst case endpoint for the acute toxicity of 1,2 -dichlorobenzene to fish.

Description of key information

The acute toxicity of 1,2 -dichlorobenzene to Rainbow trout (Salmo gairdneri, now Oncorhynchus mykiss) was investigated (Call et al 1983) under flow-through conditions for 144 h and resulted in LC50 values of 1.58 mg/L (measured concentration) after 96 h of exposure and of 1.54 mg/L after 144 h.
In a further publication (WHO, 2004), the LC50 (96 h) for the Rainbow trout determined by Call et al (1979) was reported to be in the range of 1.52 and 1.58 mg/L. This cited publication is not available and the reliablity is thus not assignable. As the authors of both publications are the same (Call et al) it is be assumed, as a worst case, that the test methods are identical. Therefore, the lowest LC50 of 1.52 mg/L is considered as worst case endpoint for the acute toxicity of 1,2 -dichlorobenzene to fish.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1.52 mg/L

Additional information

The acute toxicity of 1,2 -dichlorobenzene to Rainbow trout (Salmo gairdneri, now Oncorhynchus mykiss) was investigated under flow-through conditions for 144 h and resulted in LC50 values of 1.58 mg/L (measured concentration) after 96 h of exposure and of 1.54 mg/L after 144 h (Call et al (1983)). In a further publication (WHO, 2004), the LC50 (96 h) for the Rainbow trout determined by Call et al (1979) was reported to be in the range of 1.52 and 1.58 mg/L. This cited publication is not available and the reliablity is thus not assignable. As the authors of both publications are the same (Call et al) it has been assumed, as a worst case, that the test methods are identical.

The acute toxicity of 1,2 -dichlorobenzene to fish was also investigated under flow-through conditions by Ahmad at al (1984) following closely the method EPA-660/3 -75 -009 (1975). The endpoints were mortality (LC50) and effects on behaviour (EC50) after an exposure period of 96 hours. LC50 and EC50 endpoints were determined to be 1.61 mg/L (95% confidence interval: 1.48 - 1 .77 mg/L) and 1.55 mg/L (95% CI: 1.44 - 1.65 mg/L).

Roederer (1990) tested the freshwater species zebrafish (Danio rerio, formerly Brachydanio rerio) under flow-through conditions with analytical monitoring according to OECD guideline 203 and OECD guideline 204. The LC50 after 96 h of exposure was 5.2 mg/L (OECD 203) and the NOEC after 14 days of exposure was determined to be 0.37 mg/L (OECD 204).

Therefore, as a worst case, the lowest LC50 of 1.52 mg/L (Call et al, 1979) has been considered as the endpoint for the acute toxicity of 1,2 -dichlorobenzene to fish.