INDUSTRIAL HYGIENE TECHNICAL REPORT APPENDIX INTERPRETATION OF RESULTS SURVEY STRATEGY special media for collecting specific gases and vapors and AND SAMPLING METHODS must be used by the manufacturer’s expiration date. Air Monitoring Sampling media was placed in the breathing zone of the workers for the duration of their exposure unless Exposure monitoring was conducted using standard otherwise noted. The active sampling devices were validated industrial hygiene sampling and analytical calibrated prior to and immediately following the methods. Employees for monitoring were selected by the monitoring period using a primary calibration device contact in order to provide a good representative of the to verify the air volume for each sample collected. The various duties and processes in the plant. Air monitoring passive sampling devices were handled as specified by is routinely conducted to evaluate employees’ full-shift the manufacturer and sealed as appropriate for analyses. time-weighted average exposures. Short-term or ceiling The samples were submitted to The Hartford’s Risk limit exposures may also be evaluated. See Interpretation Engineering Laboratory which is fully accredited by The of Results below. American Industrial Hygiene Association (AIHA). Air monitoring methods can include active and passive sampling techniques. Active sampling methods use a Noise Monitoring calibrated battery operated pump attached with a hose Individual noise exposures were measured with 3M to draw air through specific collection media that is Edge noise dosimeters attached to each worker’s collar positioned in the worker’s breathing zone to represent near the ear. The dosimeters were calibrated using a 3M personal exposure. At times the collection media may AC-300 calibrator immediately before and after use. The be positioned in the general area nearby but not on the dosimeters are programmed to provide data that could be workers at breathing zone height (about 5 feet above the compared to the OSHA Action Level, and OSHA PEL. floor). This is referred to as an area sample and does not represent a personal exposure. Noise monitoring data represents full-shift time-weighted average exposures unless otherwise indicated. A summary of Passive sampling methods involve the use of a self- the monitoring results can be found in the Noise Dosimeter contained device that uses the principle of diffusion to Data Summary Tables. Area sound level measurements collect the sample. Diffusion is the mechanism of natural were collected with a calibrated 3M SD 200 Sound Level movement of gas and vapor molecules from an area of high Meter to supplement the noise dosimeter results. These concentration to an area of lower concentration. There is measurements can be found in the Sound Level Meter no need to calibrate a passive device. These devices have data sheet. 1 The Buck’s Got Your Back® AIR CONTAMINANT The OELs discussed above are established as 8 hour EVALUATION CRITERIA time-weighted average values (TWA), 15 minute short- term exposure limits (TLV-STEL), and ceiling limits Air contaminant results are compared with applicable (C). More than one OEL may apply to an airborne Occupational Exposure Limits (OELs). The OSHA contaminant. Permissible Exposure Limits (PEL), the American Conference of Governmental Industrial Hygienists Where more than one sample for an air contaminant (ACGIH) Threshold Limit Values® (TLV) and the was collected for an individual or area or when an National Institute for Occupational Safety and Health exposure to the air contaminant as for less than a full Recommended Exposure Limits (NIOSH RELs) are the shift, a time-weighted average (TWA) was calculated most widely accepted OELs in the United States. OSHA’s for comparison to the applicable OEL. The formula permissible exposure limits (PELs) are mandatory below was used to calculate the TWA: legal limits that all employers are required to comply with under penalty of law. Some states have their TWA = C1(T1) +C2 (T2)+ …Cn(Tn) own occupational safety and health regulations that T1 + T2+…Tn supersede the federal OSHA standards. Because of the complexity of changing a regulatory limit to conform to TWA = Time Weighted Average 8 hours (480 minutes) current scientific knowledge, many of the OSHA PELs C(n) = Contaminant concentration for sample n (n = 1,2….n) may not represent the best risk management choice to T(n) = Time in minutes for sample n (n =1, 2….n) prevent occupational illnesses. The ACGIH TLV® and the NIOSH REL are advisory limits that are not legally enforceable. However, OSHA may enforce them for air MIXTURES contaminants that do not have a PEL. When two or more hazardous substances have a similar toxicological effect on the same target organ or The ACGIH is a private, not-for-profit, non-governmental system their combined effect, rather than that of either scientific association, which establishes guidelines individually, should be given primary consideration. for use by industrial hygienists in making decisions In absence of information to the contrary, different regarding safe levels of exposure to various hazards substances should be considered as additive where the found in the workplace. health effect and target organ system is the same. The The ACGIH defines Threshold Limit Values® (TLVs) following formula is used to calculate the mixture TLV®: as “the time-weighted average concentration for a C1 + C2 + …Cn normal 8-hour workday and a 40-hour workweek, to which nearly all workers may be readily exposed, day T1 T2 Tn after day, without adverse effect.” TLVs® are health C is the airborne concentration of the contaminant and based values established by committees representing T is the corresponding threshold limit. scientific opinion after review of existing published and peer-reviewed scientific literature. The ACGIH If the sum of exceeds unity, the threshold limit of the re-evaluates TLVs® when new scientific data indicates a mixture should be considered as being exceeded. new health risk. Revisions and additions are published annually. The Hartford encourages the best industrial hygiene practice is to maintain exposures below the most protective OEL. Ideally exposures should be kept at least below 50% of the most protective OEL in order to allow for daily fluctuations in airborne contaminant levels. This also provides a margin of safety to ensure compliance under changing conditions. 2 AIR EXTENDED WORK SHIFTS The 90 dBA threshold columns represent the OSHA Criterion Level (CL). The OSHA Criterion Level is the OSHA standards and the ACGIH Threshold Limit equivalent 8 hour TWA noise level of 90 dBA. When Values (TLVs®) are based on a standard eight hour noise exposures reach this level engineering controls work shift. During extended work shifts, the employees’ must be implemented to reduce noise exposure to a ‘dose’ is higher because the exposure time is longer level below 90 dBA (100% dose) if feasible. Mandatory and the elimination period (period between doses) is hearing protection is required when engineering shortened. Both of these factors can potentially place controls fail to reduce exposure to a level below the the employee at higher risk of an adverse health effect. Criterion Level. When the normal work shift is ten or twelve hours, there is less recovery time between shifts for employees. It Please note that other standards have been established is important that the 8 hour time-weighted average for occupational noise exposure. The National Institute exposures be adjusted where applicable to reflect the for Occupational Safety and Health (NIOSH) and the exposure for the extended work shift. One of the most American Conference of Governmental Industrial commonly used methods to accomplish this is the Hygienists (ACGIH) acknowledge that noise exposures “Brief and Scala” model referenced by the ACGIH. The over 85 dBA, as an 8 hour average are likely to produce adjustment is made using the following formula: permanent hearing loss in some employees after years of exposure. These exposure limits are based upon 8 24 – h RF = * dosimeter settings that are different than those used h 16 for OSHA compliance. Where RF = reduction factor; and The ACGIH threshold limit value (TLV®) and NIOSH h = hours worked per shift Recommended Exposure Limit (REL) are based upon a 3 dBA exchange rate, with an 80 dBA lower limit threshold (cut-off). The American Conference of OSHA PELs are legally enforceable standards and are not Governmental Industrial Hygienists has a published adjusted with the exception of standards that allow for threshold limit value (TLV®) for noise, which is 85 adjustment such as the lead standard. Air contaminants dBA, for an 8 hour time weighted average (TWA). This with acutely irritating properties and toxicity with Ceiling exposure limit is based upon dosimeter settings that limits only are not adjusted. TLVs® for nuisance dust such are different than those used for OSHA compliance. as particulates not otherwise specified (PNOS) that are a The ACGIH TLV® and the NIOSH REL are based upon mixture of non-toxic particulate matter and can generally a 3 dBA exchange rate, with an 80 dBA lower limit be controlled through the use of good housekeeping threshold (cut-off). It is also believed that there is a practices are also not adjusted. broad range of individual differences among people in the amount of hearing loss each would suffer as a result NOISE MONITORING AND EXPOSURE of identical exposures. For these reasons The Hartford EVALUATION CRITERIA recommends that employers give consideration to these Noise monitoring results were evaluated based on the exposure limits, when making determinations regarding OSHA Occupational Noise Standard, 29 CFR 1910.95. hearing conservation measures including requiring The OSHA noise standard defines an Action Level (AL) employees to wear hearing protection when the 8 hour as the equivalent 8 hour time-weighted average (TWA) average noise exposures meet and exceed 85 dBA. noise level of 85 dBA. The HC 80 dBA threshold columns represent the OSHA Action Level.