REMOVAL_1998 - Laserfiche WebLink

Home Browse Search

Fuge z HAZARD CHARACTERIZATION AND RISK ANALYSIS Petroleum Contaminated Water and Soils Petroleum Hydrocarbons and its constituents pose health hazards in two major classifications: explosivity and toKici.ty, the extreme flammability of gasoline is commonly }:mown. The lower explosion limit (LEL) of gasoline vapor is ? ,. 3 percent in air. If the Concentration of gasoline vapor in air exceeds 1 . 3. percent ( 13,000 parts per million) and sufficient quantities of oxygen are present , then the introduction of sufficient heat, spark , or flame will result in an explosion. Prior to conducting any subsurface excavation in the vicinity of a fuel tank , the tank should be emptied of all liquid product and receive sufficient quantities of dry ice (frozen carbon dioxide) so that available oxygen is displaced from the tank: atmosphere-. A lesser known health hazard resulting from exposure to gasoline is toxicity. Over exposure to petroleum hydrocarbon vapor can cause depression of the central nervous system. Inhalation of high concentrations of gasoline can cause chemical pneumonia and/ or pulmonary edema. Repeated or prolonged skin exposure to gasoline or gasoline contaminated materials can cause dermatitis or even blistering of the skin. Several common constituents of gasoline have been shown to cause serious health problems resulting from relatively minor exposuros include henzene, toluene, meta, para, and ortho xylene=:; ethyl benzene and tetraethyl lead. Typical. percentages (by weight) of these constituents in gasol :inn are: benzene - 0. 12-_.. 50%, toluene - 2. 73-21 . 80%, wV a xylene -1 . 77•-3. 87%, para xylene -0. 77-1. 582, ortho xylene - 0. 68--2. 662, and ehty'l benzene -0. 36-2. 362. Typical percentage of tetraethyl lead is not available. Units used to describe occupational exposures to hazardous substances include: exposure limit , also known as the "threshold limit value" (TLV) , ceiling limit , and the concentration level that is " Immediately dangerous to life and health" ( IOL.H) . the exposure limit defines the maximum concentration of a substance to which one can be exposed During an 8 hour period without suffering significant health effects. The ceiling limit is the concentration level that cannot be exceeded at any time; i . e. , a suitable respirator most be worn if concentration values reach the ceiling limit..