4,4'-methylenediphenyldiisocyanate and 2,4'-diisocyanatodiphenylmethane and their oligomerisation reaction products with 2,2'-oxydiethanol, propane-1,2-diol and butane-1,3-diol

Toxicity to aquatic algae and cyanobacteria

Description of key information

In a study with Scenedesmus subspicatus (Blom et al, 1994) no toxicity was observed after 3d exposure to a loading rate of 1640mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

1 640 mg/L

EC10 or NOEC for freshwater algae:

1 640 mg/L

Additional information

The test substance is covered by the category approach of methylenediphenyl diisocyanates (MDI). Hence, data of the category substances can be used to cover this endpoint. In a limit test with Scenedesmus subspicatus (Blom and Oldersma, 1994) exposed to PMDI, no toxicity was observed after 72 hours exposure to a loading rate of 1640 mg/L. This was based on the growth rate of the algae. Hence, the 72h-NOELR was 1640 mg/L and the 72h-EC50 was > 1640 mg/L. The test was carried out according to OECD Guideline 201 and the water accommodated fraction method. The result was corroborated by the mecocosm study (Heimbach, 1993), where no effects were seen in the phytoplankton up to 1000 and 10,000 mg/L. Hence, the results indicates that MDI is not toxic to freshwater green algae.