Environmental Profiles of Chemical Flame-Retardant Alternatives for

Basis for Conclusion: No formal pyrolysis studies have been located in the literature.
Pyrolysis Products Reference
Products include phosphorous oxide Lewis, 2000 (Sax’s Dangerous Properties of Industrial
Materials)
Hydrolysis as a Function of pH:
Conclusion: The hydrolysis data are adequate.
Basis for Conclusion: Triphenyl phosphate is rapidly hydrolyzed at high pHs, more slowly
hydrolyzed at neutral pH, and only very slowly hydrolyzed at acidic pHs. The rates measured
under alkaline conditions (pH ~9) are in good agreement with one another, and the rates
measured under acidic conditions (pH ~5 or lower) are in reasonable agreement with one
another. The results for hydrolysis at pH 7 have been reported to be 19 days, 1.3 years, and 406
days. There is no apparent reason for this discrepancy in values. It appears that the half-life of
19 days was measured once (Mayer et al., 1981) and has then been repeated in other sources.
The longer half-life (ca. 1.3 years) has been reported (within acceptable experimental error) in
two independent studies (Mabey and Mill, 1978), and is consistent with the observation in
Howard and Deo (1979) that the half-life at pH 6.7 was too slow for accurate measurement over
the course of the study (14 days).
T 1/2 pH Temp. Comment Reference
19 days
3 days
7.5 days
1.3 days
7
9
8.2
9.5
25°C Mayer et al., 1981
21°C Half-life was too slow for accurate
measurement at pH 4.5 and 6.7.
Diphenyl phosphate was the only
hydrolysis product identified
Howard and Deo, 1979
1.3 years 7 25°C Rate constant = 1.7x10 -9 /sec at pH 7 Mabey and Mill, 1978
>28 days
19 days
3 days
366 days
406 days