Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Toxicity to aquatic algae data are available for 2 streams within this Category. On the basis of loading rates, the 72 hour ErL50 ranged 1.3 -1.5 mg/L

(WAF) and the 96 hour ErL50 ranged 1.4 - 1.5 mg/L (WAF). The 72 hour NOELR ranged 0.46-0.47 mg/L (WAF) and the 96 hour NOELR ranged 0.47-1.1 mg/L (WAF). On the basis of measured concentrations, the 72 hour NOEC ranged 0.30-0.37 mg/L and the 96 hour NOEC ranged 0.30 - 0.94 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:
1.3 mg/L
EC10 or NOEC for freshwater algae:
0.46 mg/L

Additional information

CAS No 68478-10-4 (ACC, 2004g): This is a GLP compliant guideline study considered adequate for assessment. The effects on growth rate (r) based upon actual loading rates for Dicyclopentadiene/Codimer Concentrate (DCPD/Codimer Concentrate) give a 72 hour ErL50 of 1.3 mg/L (WAF), a 96 hour ErL50 of 1.4 mg/L (WAF) and 72 and 96 hour NOELR of 0.47 mg/L (WAF). On the basis of measured concentrations, the 72 and 96 hour NOEC is 0.30 mg/L.

CAS No 68477-54-3 (ACC, 2004h): This is a GLP compliant, guideline study considered adequate for assessment. The effects on growth rate (r) based upon actual loading rates for Low Dicyclopentadiene Resin Oil (Low DCPD Resin Oil) gave a 72 and 96 hour ErL50 of 1.5 mg/L (WAF), a 72 hour NOELR of 0.46 mg/L (WAF) and a 96 hour NOELR of 1.1 mg/L (WAF). On the basis of measured concentrations, the 72 hour NOEC is 0.37 mg/L and the 96 hour NOEC is 0.94 mg/L.

The authors report results based on nominal loading rates (WAF) and mean measured concentrations. As the test substance is a hydrocarbon stream with various components reporting a measured concentration could be misleading as the measured concentration does not relate to a concentration of the raw stream. Instead, we have used the results reported as WAF, which better represent the potential toxicity of the test substance.