Enzymatic attack, environmentally

The hydrolysis of aromatic polyesters hke poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT) at room temperature or under environmental conditions is an extremely slow reaction and no significant direct microbial or enzymatic attack on pure PET or PBT have been observed [138]. Natural environmental processes are, thus, unable to break down products made of PET and they maintain their strength and integrity for a long period of time [139,140]. Blown PET bottles exposed to 45% relative humidity, wet soil and 100% relative humidity at 20 °C have life expectancies of 48, 35 and 27 years, respectively [139]. The life expectancies at relative humidities lower than 45% are considerably longer than that. 

Biodegradation of environmental pollutants is very largely a result of bacterial attack, and is generally believed to be enzymatically catalyzed. That being so, it would be expected that biodegradability should be susceptible to OSAR analysis, just as other enzymatically controlled processes have been shown to be. For example, Carotti et al. (1985) found fortheficin hydrolysis of a series of X-phenyl-N-(methanesulfonyl) glycinates ... 

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