Pentadecan-15-olide

Long-term toxicity to aquatic invertebrates

Description of key information

OECD Guideline 211, GLP, key study, validity 2:
21d-NOEC = 0.068 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.068 mg/L

Additional information

Two valid studies are available to assess the long-term toxicity of the substance to aquatic invertebrates.

 

The first study (Caspers, 1996), assessed as the key study, was performed on the registered substance following a method similar to OECD Guideline 211 with GLP statement. The 21d-NOEC based on reproduction and the time-weighted mean of measured test concentrations of the test media was 0.068 mg/L.

 

The second study (Sewell, 2002), assessed as the supporting study, was performed according to OECD Guideline 211 with GLP statement on the read-across substance (EC Number: 422-320-3). The 21d-NOEC based on the time-weighted mean of measured test concentrations of the test media was 0.039 mg/L. This supporting substance is considered adequate for read-across purposes (see Iuclid section 13 for justification), however, the result from the read-across substance should be considered with care.

 

Both effect patterns are similar between these two studies (100% mortality at the highest concentration in each test and no effects were observed at all other concentrations). This set of results is not ideal to derive a reliable NOEC as there is no dose response relationship, however, both the measured concentrations and effects observed of these studies seem very much consistent. The study from Caspers provides a better approximation of the NOEC value than the study from Sewell based on tested concentrations because the difference between the NOEC and the LOEC is significantly greater (a factor of 4.1) than for the study on the registered substance (a factor of 1.9). Therefore, the key value retained for the long-term toxicity to aquatic invertebrates is a NOEC value of 0.068 mg/L.