PCB-containing transformer fires: decontamination guidelines based on health considerations.

Area of Science:

• Environmental Chemistry
• Toxicology
• Public Health

Background:

• Polychlorinated biphenyl (PCB) fires, specifically those involving askarel transformers, can generate highly toxic byproducts.
• Polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzodioxins (PCDDs) are significant combustion products of PCBs.

Purpose of the Study:

• To investigate the transformation of PCBs into more toxic substances during uncontrolled combustion.
• To analyze the composition of soot from PCB fires and assess associated health risks.
• To inform the development of decontamination guidelines for structures affected by PCB fires.

Main Methods:

• Analysis of soot samples from PCB transformer fires in Binghamton, N.Y. (1981) and San Francisco (1983).
• Identification and quantification of polychlorinated dibenzofuran (PCDF) and polychlorinated dibenzodioxin (PCDD) isomers.
• Comparison of PCDF and PCDD levels to assess relative health hazards.

Main Results:

• Polychlorinated dibenzofurans (PCDFs) were identified as the most significant PCB combustion products in terms of human health risk.
• Specific PCDF isomers, particularly tetra-, penta-, and hexa- forms with 2,3,7,8-chlorination, were of greatest health concern.
• Polychlorinated dibenzodioxins (PCDDs) were not found in quantities sufficient to pose a significant health hazard.

Conclusions:

• PCDFs represent the primary toxicological concern from askarel transformer fires.
• Separate decontamination guidelines were developed based on different toxicity assumptions for each fire.
• Further research is needed to establish universally accepted decontamination guidelines for askarel fire sites.