Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

The acute toxicity of acetonitrile to fish has been studied in several freshwater species. Reported LC50 values range from 730 mg/L to 7050 mg/L. Brooke et al (1984) reported the only flow-through study with a 96-hour LC50 value of 1640 mg/L in Pimephales promelas (Fathead minnow). The lowest acute toxicity value reported for fish is a 48-hour TLm value of 730 mg/L reported by Nishiuchi in Oryzias latipes (Medaka, high-eyes). Tonogai et al (1982) reported an 48-hour LC50 value of >1000 mg/L in the same species, which is consistent with findings in other fish species tested. The reason for the low value in the Nishiuchi study is not clear.

In a guideline (OECD 204) and GLP study, MCSI of Japan (1996) reported the 21 -day NOEC for acetonitrile in fish (Oryzias latipes) to be > 102 mg/L (nominal conc.) using flow-through exposure conditions.

The acute toxicity of acetonitrile on aquatic invertebrates has been studied by several investigators. Reported LC50 values range from 400 mg/L to 8250 mg/L. The lowest values were reported by Barahona-Gomeriz et al (1994), who studied the marine crustacean, Artemia salina and reported 24 -hour LC50 values in 24, 48 and 72-hr larvae exposed to acetonitrile of 641, 521 and 400 mg/L, respectively.

21-day NOEC (reproduction) values of 160 mg/L and > 960 mg/L have been reported for acetonitrile in Daphnia magna.

Reported toxicity values for acetonitrile in freshwater algae range from 520 mg/L (8-day TT in the blue-green algae Mictocystis aeruginosa) to 7943 mg/L (48-hr EC50 in the green algae Raphidocelis subcapitata).

In a Guideline GLP study (CEMR, 2010) the effect of acetonitrile on the unicellular marine algae (Phaeodactylum tricornutum)was assessed over 72 hours using a static, sealed test system with no head spaceto avoid loss of the test substance by volatilisation from the test system.After 72 hours the following effect concentrations were calculated:

ErC50(growth rate)      9696 (95% CI: 7484 - 17597) mg/L

EyC50(yield)                 3560 (95% CI: 1604 - 7017) mg/L

The "no observed effect concentration" (NOEC) and "lowest observed effect concentration" (LOEC) for both growth rate and yield where statistically derived as 400 and 1600 mg/L respectively.

In a guideline (OECD 209) and GLP study by Brixham Environmental Laboratory (2009) the 30 -min NOEC for acetonitrile in an Activated Sludge Respiration Inhibition Test was determined to be 320 mg/L. Previous data on the toxicity of acetonitrile to aquatic microorganisms was evaluated in the EU RAR. Reported toxicity values ranged from 73 mg/L to 28,000 mg/L. The lowest value by an order of magnitude was reported by Blum and Speece (1991), a 24-hour IC50 of 73 mg/L in Nitrosomas sp., based on inhibition of ammonia consumption.