Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

One short-term toxicity study, valid without restrictions, with fish is available (Jenkins, 1989). The final test was conducted under semi-static (48 hour renewal) conditions in which groups of ten fish were exposed to 320, 560, 1000, 1800 and 3200 mg/L. The pH of each was adjusted to 7.0 before the addition of the fish. The highest nominal concentration at which no mortality occurred and the lowest at which 100% mortality occurred after 96 hours were 1000 and 3200 mg/L respectively. The calculated 96h-LC50 to fish is 1671 mg/L.

One long-term fish study, valid without restrictions, is available for PDTA-H4 (CAS 1939 -36 -2). The juvenile growth study was performed with Cyprinus carpio for a period of 28 days under semi-static conditions at neutral pH. The NOEC for growth rate was 100 mg/L PDTA-H4. Stoichiometric conversion from the PDTA (free acid) to the ammonium iron(III) salt gives a NOEC of 123 mg/L PDTA-FeNH4.

Two short-term studies, valid without restrictions, with invertebrates are available.

The final test (key study) was conducted under semi-static (24 hour renewa1) conditions (Jenkins, 1989). Daphnia were exposed to five concentrations in the range 100 to 1000 mg/L.

The pH of each was adjusted to approx. 7.0 before the addition of the daphnids. The 48h-EC50 value based on nominal concentrations was estimated to be 602 mg/L. This value is supported by a static test with Daphnia magna (Jenkins, 1991), which gave an 48h-EC50 of 687 mg/L at a pH of approx. 7.0.

In an evaluation by RIVM (2008) a long-term study with PDTA showed a 21-day NOEC for waterfleas of 16 mg/L.

Only a screeing study with algae is available. The effects in the standard algal test were due to chemical toxicity or to chelation of essential nutrients by the substance. In our opinion, the data now available presents a strong case for the assumption that the growth inhibition in the algal test is indeed due to chelation of essential nutrients rather than chemical toxicity as no toxicity upto 100 mg/L is found when optimal nutrient concentrations are used. These indirect effects may adversely affect the potential for algal growth. A review of the remaining data relevant to classification indicates that the substance should not be classified for environmental effects.