COMPLIANCE INFO_FILE 7 - Laserfiche WebLink

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SECTION 4 HAZARD EVALUATION Chemical Hazards Based on previous data collected from soil beneath the site and adjacent areas, the suspected chemical hazards of concern at the Tracy Yard site include halogenated and aromatic VOCs. These materials may exist in the soil and/or as chemicals of concern in subsurface soil and water. The hazards of the following compounds were chosen based on their toxicitv and frequency of detection at the site, but does not include all compounds detected in groundwater and soil. Halogenated Volatile Organic Compounds Most VOCs, except those known to be carcinogenic, exhibit similar hazard effects in humans. Effects on the central nervous and upper respiratory systems as well as skin irritation predominate. Therefore, although a summary of the hazards of the identified VOCs are listed separately below, additive effects of the mixture will be taken into consideration when determining established action levels. 1,1-Dichloroethane (1,1-DCA). 1,1-DCA is moderately toxic by ingestion and is an experimental tumorigen and teratogen as well as a suspect human carcinogen. The current Cal/OSHA PEL for 1,1-DCA is listed as 100 ppm. It is an oily liquid with a MW of 99, MP of -98°C, and a BP of 57.3°C. Methylene Chloride. Methylene chloride is an experimental carcinogen and tumorigen. Human systemic effects upon inhalation include: altered sleep time, convulsions, euphoria, and change in cardiac rate. It is an eye and severe skin irritant. Data in humans suggests it may be a mutagen. Methylene chloride also exhibits the unique effect of elevating the blood carboxyhemoglobin levels, similar to the effect of exposure to carbon monoxide (CO). In fact, evidence suggests that methylene chloride can convert to CO in the body. The current Cal/OSHA PEL is listed as 25 Ppm. 4-1