glyoxal … %; ethandial … %

Short-term toxicity to aquatic invertebrates

Description of key information

With high probability acutely not harmful to aquatic freshwater invertebrates. Acutely harmful to marine invertebrates.

Key value for chemical safety assessment

Marine water invertebrates

Marine water invertebrates

Effect concentration:

42 mg/L

Additional information

The result of the key study on freshwater invertebrates (BASF, 1988) indicates no acute toxicity of glyoxal (40% in aqueous solution) to Daphnia magna. The EC₅₀ value is above 100 mg/L even when it is considered that no analytical monitoring was performed since glyoxal was shown to be stable at least for this 48-h period.

With the marine invertebrate Americamysis bahia a GLP guideline study following EPA OPPTS 850.1035 (Mysid Acute Toxicity Test) is available. Based on mean measured concentrations, the 96 -h LC50 was 42.0 mg a.i./L (BASF, 2009), indicating a slightly higher toxicity towards marine organisms.

Additional data on acute toxicity to aquatic invertebrates are available from three studies with two glyoxal products of unknown composition (Parez 802 and CT-194, American Cyanamid Company). Parez 802 did not show harmful effects to Daphnia magna up to 1000 mg test mat./L (Surprenant, 1984a). The acute effects of CT-194 were tested on Daphnia magna in a 48 -h static study (Surprenant, 1984b) and on the marine shrimp Mysidopsis bahia in a 96-h static study (Irwin, 1994). When results with CT-194 are corrected for purity (assuming 40 % glyoxal in the product), the corresponding LC₅₀ values are between 10 and 100 mg/L, indicating moderate toxicity. Hence, the product CT-194 appears to be of higher toxicity than glyoxal in aqueous solution alone. Similar to the fish acute toxicity the results with the products of unknown composition are not taken into consideration due to the unclear reliability.