Laserfiche WebLink
* exposure to outside temperature extremes. <br /> • Fire, Electrical and Noise Hazards: <br /> * Underground gas and product lines, and <br /> * excessive machinery noise. <br /> Due to the nature of drilling, there is a risk for electrical shock <br /> from overhead and underground electrical lines. There is also a <br /> risk of physical injury from moving machinery and heavy drilling <br /> equipment. <br /> 4. DISCUSSION OF POTENTIAL CHEMICAL HAZARDS <br /> The Material Safety Data Sheets (MSDS) for compounds that are <br /> potentially present on site are included in Appendix A. <br /> 4. 1 Hydrocarbon vapors <br /> Hydrocarbon vapors expected to be encountered consist of gasoiline <br /> or gasoline constituents, however the levels of these vapors are <br /> expected to be at levels which should cause no deleterios effects. <br /> Exposure to elevated levels of hydrocarbon vapors presents <br /> potential health risks that need to be properly controlled. Work <br /> practices and methods will be instituted to limit exposures. Where <br /> • elevated exposures persists, respiratory protection will be the <br /> primary control method to protect personnel from inhalation of <br /> hydrocarbon vapors. The hydrocarbon vapors expected to be <br /> encountered during project activities are composed of a variety of <br /> volatile refined petroleum compounds. The majority of these have <br /> limited toxicity requiring minimal controls at the concentrations <br /> expected. <br /> Petroleum fuel and solvents consist of hundreds of chemical <br /> compounds. There are certain compounds such as Benzene that <br /> present significant hazards and must be properly controlled. To do <br /> so, a working limit of 100 ppm total hydrocarbon is proposed as the <br /> maximum acceptable level of exposure without respiratory <br /> protection. In a typical situation with 1% of the hydrocarbon <br /> vapors being benzene, a 100 ppmv concentration of total hydrocarbon <br /> will result in a breathing zone of less than 1 ppmv benzene. This <br /> level is one tenth of the current occupational Permissible Exposure <br /> Limit (PEL) for an 8 hour exposure to benzene. <br /> 4.2 Action Levels of Hydrocarbon Components in Petroleum Fuel <br /> Hydrocarbons >100ppm PEL LEL >10% <br /> If hydrocarbon vapors are noticed an evaluation of the levels will <br /> be made and work will continue or not based on this evaluation. <br />. If hydrocarbon vapors exceed 1000 ppmv or 10 ppm benzene, work will <br /> 4 <br />