Reaction mass of Ammonium dihydrogenorthophosphate and diammonium hydrogenorthophosphate.

Endpoint summary

Additional information

Toxicity to soil macroorganisms:

Only one study of reliability 1 according to Klimisch was available (Servajean, 2007) and was selected as a key study.

The toxicity of the reaction mass of ammonium dihydrogenorthophosphate and diammonium hydrogenorthophosphate was tested on earthworms (Eisenia fetida), after 14 days of exposure according to the OECD guidance 207 and in compliance with Good Laboratory Practices.First, a range-finding test was performed at 0.1, 1, 10.2, 102, and 1020 mg/kg soil dw in one replicate per test group. Secondly, a limit test at 1005.3 mg/kg soil dw in four replicates in the test group and in the control group was conducted.

At 0d, 7d, and 14d, individuals were inspected for mortality and behavior. They were also weighed at test initiation and termination for biomass changes. After 14 days of exposure, no significant effect in the range-finding test was observed neither for mortality nor for biomass changes. The limit test did not reveal further evidence of toxicity of the test item. In conclusion, based on the results from both the range-finding and the limit test, the test substance did not induce toxic effect on earthworms (Eisenia fetida) after 14d of exposure in artificial soil. For mortality and biomass changes, a NOEC >= 1000 mg/kg soil dw was calculated, and a LC50 > 1000 mg/kg soil dw was determined.

 

Toxicity to terrestrial plants:

Only one study of reliability 1 according to Klimisch was available (Servajean, 2007) and was selected as a key study.

The toxicity of thereaction mass of ammonium dihydrogenorthophosphate and diammonium hydrogenorthophosphate was tested on seedling emergence and growth of terrestrial plants as wheat (Triticum aestivum), mustard (Sinapis alba), and alfalfa (Medicago sativa) after 14 days of exposure according to the OECD 208 and in compliance with Good Laboratory Practices.First, a range-finding test was performed at 0.1, 1, 10.1, 100.6, and 1006 mg/kg soil dw in two replicates per test group. Secondly, a limit test at 100.4 and 1003.8 mg/kg soil dw in four replicates in the test group and in the control group was conducted.Emergence was recorded daily. Plants were harvested after 14 days, at least, after 50% of the seedlings had emerged in the control group. Wet weight was thus measured and dry weight after being dried at70°C. Finally plants were visually observed for evidence of phytotoxicity. After 14 days of exposure, no significant effect in the range-finding test was observed neither for seedling emergence nor for growth based on wet and dry weights. The limit test did not reveal further evidence of toxicity of the test item. No phytotoxic effects were observed and all validity criteria were met.In conclusion, based on the results from both the range-finding and the limit tests, the test substance did not induce toxic effect on wheat (Triticum aestivum), mustard (Sinapis alba), and alfalfa (Medicago sativa) after 14d of exposure in a mixture of two natural crop soils. For every species and endpoints measured a NOEC > 1000 mg/kg soil dw was determined.

 

Toxicity to soil microorganisms:

Only one study of reliability 1 according to Klimisch was available (Servajean & Dufaur-Dessus, 2007) and was selected as a key study.

Toxicity of the reaction mass of ammonium dihydrogenorthophosphate and diammonium hydrogenorthophosphate to soil microorganisms was assessed following OECD 216 guideline, under GLP. The range-finding test was realized with 5 concentrations of test substance (0.1, 1.0, 10.1, 101.1, and 1011.1 mg/kg dry soil). Except a slight promoting effect at the highest concentration, the test substance did not affect the nitrate production compared to control. Thus, the final limit test concentrations were 100.3 and 1003.4 mg/kg dry soil. Obtained results demonstrated that mean production of nitrate was 29.0 mg/kg in the amended control soil. The standard deviation of 3.8% for the nitrate concentration on day28 inthe amended soil was lower than the threshold value of 15%, and the test was considered as valid. The production of nitrate was not affected by treatment concentrations as high as 1000 mg/kg dry soil. Exposure of soil microorganisms to the test substance resulted in an EC50 (28d) > 1000 mg/kg dry soil, and a NOEC (28) >= 1000 mg/kg dry soil.