Acetonitrile

Short-term toxicity to fish

Description of key 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.

Key value for chemical safety assessment

LC50 for freshwater fish:

1 640 mg/L

Additional information

The acute toxicity of acetonitrile to fish has been studied in several freshwater species. Brooke et al, 1984 conducted exposure using flow-through apparatus; all other studies have used a static design. The fish toxicity data for acetonitrile were reviewed in the EU Risk Assessment Report (2000). A summary of the available data is shown in the table below. A single additional study has been obtained since the EU RAR. In a guideline (OECD 203) limit study under GLP conditions, MCSI of Japan (1996) reported the 96 -hr LC50 for acetonitrile in fish (Oryzias latipes) to be >100 mg/L (nominal conc.).

The acetonitrile data base includes values for Pimephales promelas, Lepomis macrochirus, Leuciscus idus melanotus, Poecilla reticulata and Oryzias latipes. The lowest value is the 48 h TLm, 730 mg/l, reported in IUCLID as toxicity for Oryzias latipes while all 48-96 h LC₅₀ values are in the g/L range. Information on additional fish species can be obtained from other sources. The WHO report (1993) includes 14 acute LC₅₀ values on seven fish species. Significant values are 24-48 h LC₅₀ values higher than 1g/L for Oryzias latipes, and two 48 h LC₅₀s, 730 and 880 mg/L on Cyprinus carpio and Ctenopharyngodon idellus respectively. The data set includes flow through and static test as well as different water pH and hardness conditions. Relevant differences on acetonitrile toxicity regarding water quality conditions were not observed.

The lowest acute toxicity value reported for fish is 730 mg/l as reported by Nishiuchi, although discrepancies between the fish species showing this toxicity appear when comparing IUCLID 2000 and the other reviews. The original paper has been submitted but it is in Japanese; however, the title and the scientific names also appear in English and indicate that the toxicity data are for the carp, Cyprinus carpio, and therefore is reported as toxicity for carp in the table below. In any case, the fish species is not relevant for this assessment and the value will be used as the lowest acute fish toxicity value.

Toxicity of Acetonitrile to Fish (EU Risk Assessment Report, 2000)

SPECIES	TEST TYPE	COMMENTS	DURATION	TOXICITY END POINT(mg/l)	REFERENCE
Pimephales promelas(fresh water)	Static nominal concentration	Used as additional information	96h	LC50=1000-1150	Henderson et al., (1961) (cited in UK and IPCS reports)
Pimephales promelas(fresh water)	Static nominal concentration	Valid	96h	LC50> 100	Ewell et al., (1986)
Lepomis macrochirus(fresh water)	Static nominal concentration	Used as additional information	24-46h	LC50= 1850	Henderson et al., (1961) (cited in UK and IPCS reports)
Ctenopharyngodon idellus	Static nominal concentration	Used as additional information	24-48h	LC50= 1950 LC50= 880	Chen, (1981) (cited in IPCS)
Poecilia reticulata(fresh water)	Static nominal concentration	Used as additional information	24-96h	LC50= 1650	Henderson et al, (1961) (cited in UK and IPCS reports)
Oryzias latipes(fresh water)	Static nominal concentration	Used as additional information	24-48h	LC50> 1000	Tonogai et al., (1982) (cited in UK and IPCS reports)
Cyprinus carpio(fresh water)	--	Valid	48h	LC50= 730	Nishiuchi (1981)
Pimephales promeles(fresh water)	flow through measured concentration	Valid	96h	LC50=1640	Brooke et al, 1984 Centre for Lake Superior Environmental studies
Leciscus idus melanotus(fresh water)	Static	Used as additional information	48h	LC50= 5850-7050	Juhnkeand Ludemann (1978) (cited in UK and IPCS report)