Glutaral

Endpoint summary

Additional information

Aquatic toxicity of glutaraldehyde was investigated with several short- and long-term toxicity test systems using a wide range of organisms representing different levels of biological organisation. Glutaraldehyde was always tested as 50% or 25 % aquatic solution; therefore, most of the effect concentrations were given as a.i. (active ingredient).

Both freshwater species, the rainbow trout (Oncorhynchus mykiss) and the bluegill sunfish (Lepomis macrochirus)

showed similar sensitivity against glutaraldehyde exposure since for rainbow trout the LC50 was 10 mg a.i./l and for bluegill sunfish it was13 mg a.i./L after 96 h of exposure under static conditions. Less toxic effects were obtained for sheepshead minnows (Cyprinodon variegatus) representing a marine fish species, with an LC50 (96 h) of 39 mg a.i./L. An Early Life-Stage toxicity test was conducted with rainbow trout (Oncorhynchus mykiss). The chronic exposure with glutaraldehyde resulted in a NOEC of 1.6 mg a.i./L.

There are several studies on the acute toxicity of glutaraldehyde to aquatic invertebrates. The EC50 values obtained for the waterflea Daphnia magna under static conditions for 48 hours was about 14 mg a.i./L.

The acute toxicity of glutaraldehyde 50% to marine shrimp Mysidopsis bahia which was tested under flow-through conditions for 96 hours resulted in an LC50 of 5.5 mg a.i/L. The LC50 of glutaraldehyde 50 % to the marine copepoda Acartia tonsa in a static test was investigated to be 3 mg ai/L.

The acute toxicity to the mussel Crassostera virginica was tested under flow-through conditions and the considered test parameter was shell growth; glutaraldehyde showed a clear effect on the growth rate of the shells, resulting in a EC50 value of 0.75 mg a.i./L and a NOEC of < 0.089 mg a.i./L. Thus, the most sensitive marine invertebrate was the mussel Crassostera virginica showing a EC50 value of 0.75 mg a.i./L.

Regarding the aquatic toxicity of glutaraldehyde algae were evaluated to be the most sensitive organism. Glutaraldehyde is highly to moderately toxic to algae, whereas the sensitivity of marine and freshwater algae to glutaraldehyde can be considered as similar. Two growth inhibition tests on freshwater algae Scenedesmus subspicatus were performed showing similar ErC50 values of 0.6 mg a.i./L and 0.61 mg a.i./L after 72 hours exposure. The ErC50 and EbC50 of glutaraldehyde to marine algae Skeletonema costatum was determined as 0.92 mg a.i./L and 0.61 mg a.i./L, respectively.

The toxicity to microorganisms by glutaraldehyde 50% was determined by measurement of oxygen consumption of activated sludge and bacterial growth inhibition to Pseudomonas putida. Glutaraldehyde showed in both tests an inhibitory effect to activated sludge (EC50 = 80 mg a.i./L) and Pseudomonas putida (EC10 = 4.4 mg a.i./L).

In conclusion, glutaraldehyde shows a very high toxicity to aquatic organisms. Furthermore, depending on local conditions and existing concentrations, disturbances in the biodegradation process of activated sludge are possible.