Registration Dossier
Registration Dossier
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EC number: 204-552-5 | CAS number: 122-52-1
Endpoint summary
Administrative data
Description of key information
Additional information
Data derived from SIDS Initial Assessment Report For SIAM 16 (Triethyl Phosphite), 2003 Paris.
The main degradation process in water is hydrolysis. In acid solution (pH= 4) triethyl phosphite reacts immediately with water to form diethyl phosphite and ethanol. At pH 7 triethyl phosphite hydrolyses completely within 20 minutes, after 3 hours 89.3% diethyl phosphite and 10.7 % monoethyl phosphite are formed. At pH 9 triethyl phosphite is more stable (t1/2water: ca. 5.1 hours), 70 % of the substance remains unhydrolyzed after 3 hours. In 2 tests on ready biodegradation triethyl phosphite was degraded by 49 - 69 %. Therefore, it did not reach the criteria for ready biodegradability. However, it can be assumed that triethyl phsophite is inherently biodegradable. From two studies on the ready biodegradation of diethyl phosphite it can be concluded that diethyl phosphite is not readily biodegradable but can also be regarded as inherently biodegradable. From the degradation curve it can be assumed that hydrolysis was the prerequisite for biodegradation. It is expected that in the atmosphere a degradation of triethyl phosphite occurs due to indirect photolysis (t1/2air: ca. 6.6 hours). As the substance hydrolyses under environmental conditions the calculation of a Mackay distribution model is also not appropriate. Due to rapid hydrolysis bioaccumulation of triethyl phosphite is not expected. The calculated log Kow value for diethyl phosphite (log Kow = -0.2) indicates no bioaccumulation potential of the hydrolysis product.
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