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Ecotoxicological information

Endpoint summary

Administrative data

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Additional information

Freshwater aquatic toxicity studies with MAPTAC were conducted in fish, invertebrates, algae, and microorganisms.

 

Short-term toxicity to fish

In a 48-h acute toxicity study, golden orfes (Idus melanotus HECKEL) were exposed to MAPTAC (50±1% a.i. according to supplier) in nominal concentrations of 2000, 5000 and 10000 mg/L under static conditions.

The 48-h EC50 was > 5000 mg a.i./L). The 48-h NOEC was 5000 mg a.i./L.

   

Short-term toxicity to aquatic invertebrates

No data on short-term toxicity of MAPTAC are available. In accordance with REACH regulation Annex VII, 9.1.1., column 1, long-term toxicity data are provided instead.

 

Toxicity to aquatic algae

In a 72 hour acute toxicity study, the cultures ofDesmodesmus subspicatusCHODAT SAG 86.81 were exposed to MAPTAC (50% in aqueous solution; exposure concentration corrected for purity) at nominal and measured concentrations of 0 (control) and 100 mg a.i./L under static conditions in a limit test in accordance with the OECD guideline 201 (adopted 23 March 2006). 

No growth and yield inhibition were observed. Microscopic evaluation of the cells at start and end of the incubation period revealed no morphological abnormalities.

The NOEC based on growth rate and yield ware both 100 mg a.i./L. The EC10 based on growth rate and yield were both > 100 mg a.i./L. The EC50 based on growth rate and yield were both > 100 mg a.i./L.

 

Long-term toxicity to fish

Long-term testing in fish is waived for MAPTAC since the substance is inherently biodegradable. The risk characterisation shows that the PEC/PNECaqua ratio for the aquatic environment is <1, indicating no need for further information or testing. According to REACH regulation Annex IX, 9.1. column 2, long-term toxicity testing shall only be considered when the chemical safety assessment indicates the need for further investigations. Thus, no long-term toxicity testing is required for MAPTAC.

 

Long-term toxicity to aquatic invertebrates

The 21-day-chronic toxicity of MAPTAC (50.6% in aqueous solution) to Daphnia magna Straus was studied under static renewal conditions according to OECD guideline 211 (adopted 3 October 2008). Daphnids were exposed to control and test chemical at nominal concentrations of 0 (control), 50.0, 100, 200, 400 and 800 mg/L, corresponding to 0, 25.3, 50.6, 101, 202 and 404 mg a.i./L. Measured concentrations were within 95 and 106% of nominal concentrations. Therefore, all effect values given are based on the nominal concentrations of the test item.

The sublethal effects included were reproductive output, number of living offspring per parent, occurrence offirst brood, intrinsic rate of natural increase, occurrence of aborted eggs and stillborn juveniles and body length of the parental daphnids

Based on the biologically significant variation of the reproductive output at the concentration levels 200 and 400 mg/L, the No Observed Effect Concentration after 21 days was assessed at 100 mg test item/L (corresponding to 50.6 mg a.i./L) and the Lowest Observed Effect Concentration was assessed at 200 mg test item/L (corresponding to 101 mg a.i./L).

The test item induced biologically significantadult mortality in concentration levels of 400 mg/L (60%) and 800 mg/L (100%) after 21 days.In the concentration levels 50.0 to 200 mg/L and in the control all parental daphnids survived till the end of the test after 21 days.

The 21 day EC10 based on reproductive effects was 53.6 mg a.i./L (95% CL <25.3 – 76.4 mg a.i./L).The 21-day NOEC based on reproduction was 50.6 mg a.i./L.

 

Toxicity to microorganisms

In a 16-h toxicity study conducted according to the Bringmann-Kühn test,cultures of Pseudomonas putida were exposedto MAPTAC.The EC10 was 9000 mg a.i./L.

 

In conclusion, the lowest aquatic toxicity value for MAPTAC was the NOEC of 50.6 mg a.i./L, based on the 21-day long-term toxicity test with Daphnia magna.