3-chloropropene

Endpoint summary

Additional information

The acute toxicity of 3-chloropropene was tested in a number of aquatic freshwater species from different trophic levels. The study duration ranged from less than 24 hours to 14 days. All available effect levels were based on nominal concentrations as none of the studies used analytical techniques to verify the concentrations of the substance in the test solutions. The majority of studies were carried out in static test systems, i.e. the test substance was once added at the beginning of the test. In addition, it is not fully clear to what extent the studies accounted for the volatility of 3-chloropropene. Despite these uncertainties the set of studies give a relatively clear and consistent picture of the aquatic toxicity of 3-chloropropene. Fish tend to be most susceptible with regard to exposure to the substance. The LC50 values found in 24- to 96-hour studies performed with different fish species ranged from 6.9 to 70 mg/L. The acute toxicity study using a semi-static test system (CITI 1992) produced also the lowest LC50 value of 6.9 mg/L.

Carassius auratus       24-hour LC50 = 10 mg/L       Bridie et al. (1979)

Leuciscus idus melanotus       48-hour LC50 = 70 mg/L       Juhnke and Lüdemann (1978)

Oryzias latipes48-hour       LC50 = 6.9 mg/L       CITI 1992

Carassius auratus       96-hour LC50 = 21 mg/L       Pickering and Henderson (1966)

Lebistus reticulates       96-hour LC50 = 51 mg/L       Pickering and Henderson (1966)

Lepomis macrochirus       96-hour LC50= 42 mg/L       Pickering and Henderson (1966)

Pimephales promelas       96-hour LC50 = 20-24 mg/L       Pickering and Henderson (1966)

A semi-static study on the prolonged toxicity of 3-chloropropene to fish was performed over a period of 14 days (Hermens et al. 1985). The study used Poecilia reticulata and found a lower LC50 value than in the acute toxicity tests of 1.2 mg/L and this value will be considered in the derivation of the aquatic PNECs.

The toxicity of 3-chloropropene to daphnids was tested in a standardised static test system with Daphnia magna, which did, however, not sufficiently account for the volatility of the test substance (Bringmann and Kühn 1977). The EC50 value after 24 hours that was established on the basis of immobility of the daphnids was 250 mg/L. Also the acute toxicity to green algae (Scenedesmus quadricauda) and blue-green algae (Mircocystis aeruginosa) was tested in the standardised cell multiplication inhibition test (e.g., Bringmann and Kühn 1975, Bringmann and Kühn 1980). These tests used adequately closed vials and thus accounted for the volatility of 3-chloropropene. The NOEC values based on inhibition of cell multiplication were 6.3 mg/L (S. quadricauda) and 8.2 mg/L (M. aeruginosa).

Additional information on the acute toxicity of 3-chloropropene is available from tests performed with protozoa. Bringmann and Kühn (1981) used the same cell multiplication inhibition test as for algae to test the toxicity of the substance to Chilomonas paramecium (48 hours) and Entosiphon sulcatum (72 hours). Closed vials were used in these tests. The resulting NOEC values were 8.6 and 8.4 mg/L, respectively. The acute toxicity of 3-chloropropene to the larvae of the clawed toad (Xenopus laevis) was investigated in a static test systems with covered glass basins and at least five test concentrations (deZwart and Sloof 1987). The established LC50 value was 0.34 mg/L, which is the lowest of all reported effect levels. However, as the LC50 value is based on a single test and as no second test was performed to verify this level the significance of the result is not fully elaborated. The information on the toxicity of 3-chloropropene to micro-organisms in sewage treatment plants is somewhat ambiguous and the available studies are not fully reliable. Bringmann and Kühn (1976) performed a test with Pseudomonas putida investigating the inhibition of cell multiplication. It is not clear if the test vials were properly closed during the 16-hour duration of the study. The NOEC in that study was 115 mg/L. Two additional tests on the inhibition of nitrification were carried out with samples of activated sludge taken from wastewater treatment plants. While the one study reported an EC75 value of 180 mg/L after 2.5 hours of exposure of aerated sludge-test substance solution-mixture (Tomlinson et al. 1966) the other study reported a NOEC of 120 mg/L after 2.5 hours of exposure of aerated sludge-test substance solution-mixture (Wood et al. 1981).