Indeno[4,5-d]-1,3-dioxin, 4,4a,5,6,7,8,9,9b-octahydro-7,7,8,9,9-pentamethyl-

Long-term toxicity to aquatic invertebrates

Description of key information

A 21-day Daphnia study according to OECD TG 211 was conducted. No immobilisation or reproductive effects were seen resulting in a NOEC of >=0.891 mg/l. This NOEC value will only be used to decrease the assessment factor when deriving PNECs because this NOEC is a > value.  

Additional information

The test substance was tested to assess its potential to cause reproductive toxicity to Daphnia magna, using the procedure outlined in the OECD Guideline 211 for the "Daphnia magna Reproduction Test" (OECD 1998a). This test was conducted to assess the effects of the test substance on Daphnia magna by recording the number of neonates produced over a 21-d exposure period, under controlled conditions, using nominal test substance concentrations of 0.000, 0.033, 0.066, 0.131 , 0.262, 0.525, and 1.050 mg/L. Corresponding time-weighted mean measured concentrations were determined to be <0.0 1 , <0.027, 0.049, 0.096, 0.223, 0.452, and 0.891 mg/L, respectively. The analytical detection limit was 0.01 mg/L, and the lowest quantitation limit was 0.027 mg/L. Adult survival was 89 % to 100 % among the treatments. Mean number of neonates per surviving parent animal was 70 to 86. There were no significant differences in mean number of neonates, body length, or dry weight per surviving parent animal (p > 0.05). For all of the end points assessed in this study, the no observed effect concentration (NOEC) was 0.891 mg/L (based on time-weighted mean concentration) and the lowest observed effect concentration (LOEC) was >0.891 mg/L. Due to a lack of concentration-response, the median effective concentration (EC50) for reproductive output could not be calculated and was estimated as >0.891 mg/L.