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Ecotoxicological information

Toxicity to microorganisms

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Description of key information

An EC50 value of >1000 mg/L has been determined for the test substance in an activated sludge respiration inhibition (ASRI) test.

Key value for chemical safety assessment

Additional information

The assessment of the toxicity of the substance to microrganisms for the purposes of hazard classification is based on the available test data.  

ATMP-xNH4 will however dissociate when it is released into aqueous environments to yield ATMP and ammonia. ATMP and ammonia are therefore be treated separately for the purposes of deriving PNECstp for sewage treatment plant.


A 30-minute EC50value of >1000 mg/L has been obtained in an activated sludge respiration (ASRI) test with ATMPxNH4.

While a non standard respiration inhibition study with ATMP acid has determined a 30 d NOEC value of 200 mg active acid/l.


Typical levels of free ammonia in municipal WWTPs range from ca. 12-50 mg/l in the WWTP collection system (Lehr, Jay; Keeley, Jack; Lehr, Janet Water Encyclopedia, Volumes 1-5. (section 1.4.49). John Wiley & Sons.). A NOEC of >50 mg/l, can therefore be predicted for ammonia toxicity to microorganisms.


A number of non-standard studies are available giving evidence that ATMP has no inhibitory effect on micro-organisms at concentrations up to ca. 200 mg/L.