Laserfiche WebLink
<br />Geocon Project No. S2170-07-12 - 14 - June 6, 2022 <br />CHEMICAL NAME CAS # ROUTES OF ENTRY PUBLISHED EXPOSURE LIMITS <br />CATEGORY CONCENTRATION SOURCE <br />Lead, Elemental & Inhalation <br />Inorganic Compounds Ingestion <br />7439-92-1 <br />Lead Chromate Inhalation <br /> Ingestion <br />PEL-TWA† 50 µg/m3 Cal/OSHA <br />Action Level 30 µg/m3 <br /> <br />PEL-TWA as Pb 0.02 mg/m3 <br />PEL-TWA as Cr 0.005 mg/m3 <br />†PEL – Cal/OSHA Permissible Exposure Limit; TWA – 8-hour time-weighted average concentration <br />4.0 GENERAL HEALTH AND SAFETY REQUIREMENTS <br />4.1 Air Monitoring <br />4.1.1 VOCs <br />The necessity for evaluating potential airborne concentrations of vapors from VOCs will be determined <br />during the project by the PSO. Based on preliminary information from previous sampling and <br />characterization activities conducted at these sites, the potential for significant exposure to these <br />contaminants is low. <br /> <br />If necessary, based on observations, odors, or other information which becomes available during <br />sampling activities, potential exposure to volatile organic hydrocarbons will be evaluated using a <br />direct-reading photoionization detector (PID) equipped with a 10.2 electron volt probe; measurements <br />will be made at the top of the monitoring well and in the operators breathing zone. <br /> <br />All measurements shall be recorded in the field logbook. The frequency or need for continued sampling <br />will be based on results from initial measurements. Justification for discontinuing measurements shall <br />also be recorded in the field logbook. <br /> <br />The PSO shall be responsible for interpreting monitoring data and upgrading or downgrading the level <br />of protection during field activities according to the following guide: <br /> <br />Response Criteria For Airborne Vapor Concentrations <br />(measured at breathing zone level) <br />READING LEVEL OF PROTECTION <br />0 ppm or Background <br />(as measured up-wind of sampling location) Level D <br />Background - 5 ppm above background <br />> 5 ppm up to 10 ppm above background Level D w/ continuous monitoring <br />>10 up to 300 ppm above background Level C <br />>300 ppm above background Stop Operations <br />Move Up-Wind <br />