Reaction mass of 4-hydroxybenzene-1,3-disulphonic acid and 4-hydroxybenzenesulphonic acid and sulphuric acid and water

Short-term toxicity to aquatic invertebrates

Description of key information

EC50 for freshwater invertrebrates = 100 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

There are 3 short-term acute studies with Daphnia Magna. The key study is a 2005 Guideline (OECD 202) study with a 99.8% analyticaly pure benzenesulfonic acid (CAS No. 98-11-3) conducted under GLPs. It is a well documented limit test with analytical confirmation. There was no mortality or immobility observed at 100 mg/L (nominal) / 103 mg/L measured. The test conditions were confirmed to be valid and the reference substance produced expected results. The 48h-EC50 for 98-11-3 is reported as >100 mg/L.

The 2005 study with benzenesulfonic acid is the only one of the three studies with sufficient details and adherence to OECD guidelines to use to establish the 48h-EC50 of >100 mg/L. The other 2 studies give support to this endpoint value.

There is a 1995 supporting study conducted following OECD 202 but without analytical confirmation and no confirmation of GLP compliance. This limit test was conducted with a 65% pure (in water) benzenesulfonic acid (CAS No, 98-11-3). There was no toxicity observed and the 48h-EC50 is reported as >100 mg/L. There is also a 1983 study of p-toluenesulfonic acid (CAS No. 104-15-4) designated a "weight-of-evidence" study. There were multiple, nominal test concentrations (5000, 1000, 100, 10 and 0), however, the exposure duration was 24 hours instead of the required 48 hours. There was no toxicity in the 0 and 10 mg/L exposures, 5% at 100 mg/L, 35% at 1000 mg/L and 10% at 5000 mg/L. There are insufficient details and no plausible explanation for the lower toxicity at 5000 mg/L. The results indicate the 24h-EC50 is above 1000 mg/L.