Biodegradation probability

Data regarding the transformation and degradation of hexachlorobutadiene in soil were not located. However, based on the observation that hexachlorobutadiene was completely biodegraded in water under aerobic conditions (Tabak et al. 1981), biodegradation probably occurs in nonarid soils as well. 

Howard, P.H. and Meylan, W.M. Biodegradation Probability Program, Syracuse Research Corporation, Syracuse, NY (1992). 

Structural fragments + MW Biodegradability probability + Numerical score for hrs, days, wks, months, longer... 

The Biodegradability Probability Program has been developed over a period of years and is still being refined. As indicated in Table 12.6, the original model was developed with 35 structural fragments whose coefficients were developed by linear and non-linear regression to an experimental "weight-of- evidence" evaluation for 264 chemicals from the BIO-DEG database (Howard et al., 1987). Chemicals were used only if two or more... 

Biodegradability Probability Program Structural Fragments and Coefficients (Boethling et al., 1994). 

Sample Biodegradation Probability Program Calculations for Benchmark Chemicals. 

Syracuse Research Corporation. 1996. BIODEG Program. Estimation of Biodegradation Probability, (computer software for MS-DOS MS-Windows 3.1). http / /esc.syrres.com. North Syracuse, NY. 

Also in the EU TGD (EC, 1996) it is recommended that estimated biodegradability by use of the Biodegradation Probability Program is used only in a conservative way, i.e. when the programme predicts fast biodegradation, this result should not be taken into consideration, whereas predictions of slow biodegradation may be considered (EC, 1996). 

Thus, the use of results of the Biodegradability Probability Program in a conservative way may fulfil the needs for evaluating biodegradability of some of the large number of substances for which no experimental degradation data are available. 

Syracuse Research Corporation. Biodegradation Probability Program (BIOWIN). Syracuse. N.Y. http //esc.syrres.com/ escl/biodeg.htm... 

Selection from set A of those substances that may reach the human environment at exposure levels that may be significant (set B). Set B should include substances that may affect environmental processes of immediate importance to human health, such as the activity of sewage degrading organisms. Assessment of probable exposure levels should take into account such data as production, use and disposal quantities, octanol-water partition coefficients and bioaccumulation measurements, volatility, measures of persistence and biodegradability, probable environmental mobility, and major ecological effects. 

One of the more popular group contribution QSDRs is a series of models/ collectively referred to as biodegradability probability program (BIOWIN), which consists of six aerobic biodegradation models [6,7,17] and one anaerobic model which has been recently released [18]. These models are available for free from U.S. EPA as part of the EPl Suite (Table 1). 

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