Acetaldehyde oxime

Endpoint summary

Additional information

 

Overall, test reports are available describing the acute aquatic toxicity to the three trophic levels. There are three test reports available describing the acute toxicity towards fish, in three different species (Buccafusco 1981a, 1981b and Geiger et al. 1990). There is one report describing the short-term toxicity to Daphnia magna (Palmieri, 1981) and one describing the toxicity towards freshwater algae, Selenastrum Capricornutum (van Dijck et al., 2005).

 

In the two studies by Buccafusco (1981a and 1981b) the same protocol was followed with different fish species. Study reports were well documented and performed according to the guidelines existing at that time, therefore both studies received a K2 score.

Fish were exposed for 96h to 6 different concentrations of Acetylaldehyde Oxime. The test substance was not measured in any of the tests.

In the study with Bluegill sunfish (Lepomis macrochirus), a 96h LC50 of 30 mg/L was reported. The NOEC for that same species (96h) was 23 mg/L. In the test with rainbow trout (Oncorhynchus mykiss), a 96h LC50 of 55 mg/L was reported together with a NOEC of 15 mg/L. The results of these two tests are in accordance with a more recent study by Geiger et al. (1990) in which fathead minnows (Pimephalus promelas) were exposed to AAO. In this study they did measure active ingredient concentrations and demonstrated a 96h LC50 of 76 mg/L.

 

The short-term toxicity study with Daphnia magna by Palmieri (1981) is also a well-documented study performed according to the guidelines active at that moment. The nominal concentrations tested ranged from 638 to 966 mg/L, however the concentrations were not verified in that study. The 48h EC50 value for Daphnia magna was determined at approximately 770 mg/L, while the NOEC was clearly below 638 mg/L, which is the lowest tested concentration in this study.

 

The most recent study documenting aquatic toxicity, is the study on aquatic algae by van Dijk et al. (2005). In this study,Selenastrum capricornutum, was exposed for 72hr according to the OECD203 guideline protocol with slight modifications as suggested by Mayer et al. (2000) to enable testing in closed bottles. Test concentrations were analytically verified in this test. The ErC50 determined in this study after 72h was 74 mg/L (based on growth rate), the ErC10 was 11 mg/L.

 

A well-documented study is available by Stevenson and Blum (1981). From this study it was concluded that AAO does not inhibit activated sludge microorganism metabolism at the test concentrations studied, concentrations ranging from 5 to 5000 mg/L. As no toxicity/inhibition was noted at any of the tested concentrations, the IC50 was set at > 5000 mg/L.

 

Short-term toxicity endpoint	Effect	Reference
Fish Lepomis macrochirus	LC50 (96h) = 30 mg/L  NOEC (96h) = 23 mg/L	Buccafusco, 1981a
Fish Oncorhynchus mykiss	LC50 (96h) = 55 mg/L  NOEC (96h) =15 mg/L	Buccafusco, 1981b
Fish Pimephalus promelas	LC50 (96h) = 76 mg/L	Geiger et al. 1990
Invertebrate Daphnia magna	EC50 (48h) = ca. 770 mg/L NOEC (48h) = 638 mg/L	Palmieri, 1981
Algae Selenastrum capricornutum	ErC50 (72h) = 74 mg/L ErC10 = 11 mg/L	Van Dijck et al. 2005
microorganisms	IC50 > 5000 mg/L	Sevenson and Blum (1981)