α-chlorotoluene

Short-term toxicity to aquatic invertebrates

Description of key information

Acute toxicity to daphnids:

NOEC(48h) = 2.5 mg/L for Daphnia magna (EPA guideline 660/3-75-009) (based on nominal concentration)

NOEC (48h) = 1.0 mg/L for Daphnia magne (OECD TG 202) (based on nominal concentration)

EC50 (48h) = 6.1 mg/L (95% C.I.: 5 - 10 mg/L) for Daphnia magna (EPA guideline 660/3-75-009) (based on nominal concentration)

EC50 (48h) = 3.2 mg/L for Daphnia magna (95% C.I. 2.8 - 3.8 mg/L) (OECD TG 202)

EC50 (24h) = 4.2 mg/L for Daphnia magna (OECD TG 202)

EC50(24h) = 8.4 mg/ for LDaphnia magna  (similar procedure to OECD Guideline 202)

EC50(24h) = 1.3 mg/L (P 95%: 1.1 - 1.6 mg/L) for Daphnia magna (strain IRCHA) (similar procedure to OECD Guideline 202)

Acute toxicity to shrimps:

LC50(96h) = 3.9 mg/L (95% CI: 3.3 - 4.6 mg/L) nominal concentrations and 0.14 mg/L measured concentrations for Penaeus setiferus (EPA guideline 660/3-75-009 which is similar to EPA OPPTS 850.1045)

Additional information

Several studies are available for acute toxicity on aquatic invertebrates.

-      The OECD SIDS (1998) describes a test performed by the Environment Agency of Japan (1995). The effect onDapnia magnawas assessed in a 48-hour semi-static acute toxicity tests, closed system, according to OECD Guideline 202. The EC50 of the invertebrateDapnia magna after 24 hours and 48 hours exposure was determined to be 4.2 mg/l and 3.2 mg/l respectively. The NOEC was determined to be 1.0 mg/l.

Additional to OECD SIDS publication in 1998, three other studies are available (Calvert and Adams, 1982 and Bringmann and Kühn, 1977 and 1982).

 

-      In Calvert and Adams (1982), a GLP-compliant acute immobilization test according to guideline EPA 660/3-75-009, which is similar to OECD Guideline 202 was performed.Daphnia magnawas exposed under static conditions to benzyl chloride for 48 hours. Three series of 10 specimens were tested at nominal concentrations of 0.62, 1.25, 2.5, 5 and 10 mg/L. Prior to making the test solution, benzyl chloride was first dissolved in dimethylformamide. Hence besides the control a solvent control was added to the test. Furthermore, dissolved oxygen, pH, alkalinity, hardness and temperature were measured during the test in all vessels. The EC50(48h) was 6.1 mg/L (95% C.I.: 5 - 10 mg/L) and the NOEC(48h) was 2.5 mg/L based on nominal concentrations. Thus, benzyl chloride is not hazardous toDaphnia magnain the conditions tested according to the CLP regulation (EC) N° 1272/2008.

 

-      Bringmann and Kühn (1977, 1982) also used an acute immobilization test similar to OECD Guideline 202 to exposeDaphnia magna(strain IRCHA in the study of 1982) to benzyl chloride under static conditions for 24 hours. In 1982 these authors assessed the EC0(24h) and EC100(24h) at 0.66 and 5 mg/L respectively. In both studies, series of 10 dapnids of max. 24h old (3 replicas in 1977 and 2 in 1982) were exposed to a dilution series ofthe test substance. In the test of Bringmann and Kühn (1977) the estimated EC50(24h) was 8.4 mg/L. According to the study of these authors in 1982 the estimated EC50(24h) of benzyl chloride was 1.3 mg/L (P 95%: 1.1 - 1.6 mg/L). The latter test used a reference_substance (potassium dichromate) for which a valid result was obtained (average EC50: 1.3 mg/L; required range: 0.9 - 1.9 mg/L). In view of these results, benzyl chloride cannot be classified based on the CLP regulation (EC) N° 1272/2008 since the test duration was 24h instead of the required 48h.

 

-      Curtis et al. (1979) performed a short-term toxicity study on shrimps (Penaeus setiferus) according to guideline EPA 660/3-75-009 which is similar to EPA OPPTS 850.1045. The test animals were exposed under static conditions to benzyl chloride during 96h. Four series of three organisms were exposed to a range of nominal concentrations with at least a dilution factor of 60% and at least two controls were included. The slow degradation of benzyl chloride into benzyl alcohol and HCl in the dilution water did not lead to a decrease in pH to a toxic level nor cause any oxygen depletion problem. Furthermore the percentage of mortality in the controls during the 96h test period was below 10%. The LC50(96h) was 3.9 mg/L (95% CI: 3.3 - 4.6 mg/L) based on nominal concentrations and 0.14 mg/L based on measured concentrations. Based on the classification categories given in the CLP regulation (EC) N° 1272/2008 no classification for benzyl chloride can be done as for crustaceans as a EC50 after 48h is requested.

 

In conclusion, the acute toxicity test performed by Calvert and Adams in 1982 clearly showed that benzyl chloride was non hazardous toDaphnia magnaaccording to the CLP regulation (EC) N° 1272/2008. The other studies however could not be used for classification due to different exposure duration than requested in the CLP regulation.