Silica Control Programs in Construction: Guide for Managing: Exposure Assessment for Crystalline Silica   Overview Section 1: Planning When to Plan Who Does the Planning What Plans Need to be Made Section 2: Implementing Suggestion Box: When to Schedule Monitoring Section 3: Managing & Responding to Results Managing the Results Responding to Elevated Results Section 4: Infosheets, Sample Forms, & Further Information Infosheet 1: Hiring an IH Consultant Infosheet 2: Project Information for the IH Checklist 1: Reporting Results to Workers Sample Recordkeeping Form Sample Air Monitoring Results Reporting Form/TLV (Individual) Sample Air Monitoring Results Reporting Form/TLV (Group) Sample Air Monitoring Results Reporting Form/OSHA PEL (Individual) Sample Air Monitoring Results Reporting Form/OSHA PEL (Group) Background for Understanding the Crystalline Silica Monitoring Report Silica Facts Sheet Overview Exposure assessment, or monitoring, measures workers' exposure to airborne contaminants during the performance of their jobs. Why perform monitoring? It is required by OSHA under the Special Emphasis Program (SEP) for Silicosis Required by some owner specifications The exposure level determines what has to be done to protect workers, including: the need for engineering controls the effectiveness of engineering controls the type of respirators required on the job Overview of the Tasks 1. Planning a) Designate a Silica Program Manager (SPM) b) Identify tasks/trades that generate silica dust c) Hire IH consultant 2. Implementing a) Select tasks to be monitored b) Schedule monitoring c) Prepare personnel for monitoring d) Organize day of monitoring 3. Managing and Responding to Results a) Review IH report and results of monitoring b) Respond to elevated results c) Provide results to workers d) Maintain records of results — This Guide will elaborate on these tasks — Planning When to plan At the same time the project is being planned No later than during job mobilization If job has started, or dusty tasks have begun, plan fast to do what has to be done! Who does the planning Corporate safety office (where applicable) or management at the site begins the planning and appoints the Silica Program Manager (SPM). SPM should have silica awareness training and some knowledge of dust hazards and their control Planning is usually done by the SPM and project management What plans need to be made Identify tasks/trades with potential for generating silica dust. SPM needs to be familiar with scope of work throughout the course of the project since tasks or intensity of work often vary during the life of the project. Hire an Industrial Hygiene (IH) Consultant - See Infosheet 1 (B-11) and Resource (F-2) Supply IH consultant with information to help him/her gain an understanding of the project - See Infosheet 2 (B-13) To do their job well, the consultant will have to have a sense of such items as the scope of work, the tasks being performed, and the number of workers engaged in these tasks. In the meantime: employees should be protected with respirators as soon as dusty work begins. Refer to the Guide for Managing a Respiratory Protection Program for Crystalline Silica. Section 1 Notes Selecting an IH you can work with is important. The IH provides information that is used to select the appropriate level of worker protection. OSHA or the owner may review this information at any time. The IH can help interpret OSHA standards Implementing The IH performs the monitoring; the SPM organizes things so that the IH can do the job with the least disruption to the project. Select tasks to be monitored Review all silica generating tasks Conduct walkthrough of site with IH Make sure the IH sees all silica generating tasks Orient IH to safety issues at site Schedule monitoring — See Suggestion Box below Determine work schedule with project manager Select day when activities are going to be representative of an average workday Call IH consultant and schedule Prepare personnel for monitoring Arrange with site supervisor/foreman the day before - the fewer surprises the better. Inform workers and unions that monitoring is taking place A toolbox talk on what to expect and an explanation of monitoring the week before is suggested Organize day of monitoring Review sampling plan with IH Ensure all tasks and highest exposures are selected Ensure IH has access to site and workers Review with IH tasks/locations/workers to be monitored Accompany IH to sampling locations Introduce IH to workers and supervisors Summarize day with IH Meet with IH at end of work shift for a quick review of the day's activities. Ask if there were any problems that could affect results or any situations in need of immediate response. Section 2 Notes The SPM has a detailed knowledge of the site (exposures/tasks). His job is to communicate relevant information to the IH so he/she can do the best possible job. Suggestion Box: When to Schedule Monitoring Beginning of job (to make an initial determination) At least every six months if exposure is greater than 1/2 the Threshold Limit Value (TLV) - see Note below. At least every three months if exposure is above the TLV Any major variation in the work process can reduce or increase exposure levels. Remonitor whenever changes occur. New tasks and/or tools are introduced Crew size increases Work configuration changes significantly (enclosure, confined area) Increase in number of hours worked Even with the best intentions, things go wrong. Here are some scheduling pitfalls that managers have to deal with: Monitoring cannot be conducted as planned due to such factors as: Weather Change in work plans for the day Equipment breakdown Monitoring begins but cannot be finished because of above A worker who is being monitored is assigned to another task Work is unusually light and it is difficult to get a representative sample If such things happen, reschedule as soon as possible Note: Occupational Exposure Limit Information This Guide refers to two occupational exposure limits for crystalline silica: the ACGIH TLV and the OSHA Permissible Exposure Limit (PEL). The TLV is 0.05 mg/m3. The OSHA PEL is roughly equivalent to 0.1mg/m3, but it must be calculated for each sample. For more information, refer to the Background for Understanding the Silica Monitoring Report (B-27). We choose to use the TLV because it is more protective and much more straightforward to apply. Managing & Responding To Results The SPM has responsibilities for reviewing the IH report, informing workers and keeping records. These tasks are described below. Managing the Results Review IH report and results of monitoring. Compare results to ACGIH-TLV or OSHA PEL Review IH recommendations Initiate response if necessary - See Responding to Elevated Results, on next page. Provide results in writing to each monitored workers within 5 days of receipt of results. See Sample Air Monitoring Results Reporting Form (Individual B-19/23) Distribute during weekly toolbox talk or with paychecks Attach Silica Fact Sheet (B-29) Provide results to all workers potentially exposed to silica dust. See Air Monitoring Results Reporting Form (Group) B21/25 Post prominently in change room or distribute to workers Use Checklist 1: Reporting Results to Workers group results file folder (B-15) Prepare and schedule a toolbox talk to review the results Maintain records of results Use Sample Recordkeeping Form (B-17) Responding to Elevated Results Monitoring results above the TLV or PEL might indicate a problem with engineering and work practice controls. Consult the Guide for Managing Engineering & Work Practice Controls for further guidance on troubleshooting. The following points summarize the main steps to be taken: Make sure there are controls in place. Check out the equipment to make sure it is functioning. Talk to the workers, to find out if: engineering controls are working properly they are familiar with the equipment they have any suggestions for improving existing controls they use the controls and, if not, why not what they do when the equipment isn’t working properly Hold a safety meeting with managers and a toolbox talk with workers about the controls. Investigate with them if the controls are suited to the site and the particular application. An investigation of other controls may be in order. If problems are found and corrected, reschedule monitoring. Given the measured exposure, ensure that the types of respirators worn by the workers are sufficiently protective and are being used properly. Section 3 Notes When monitoring workers for exposure to crystalline silica, dust is passed through a cyclone to separate out large dust particles so that only the smaller particles are collected on the filter. These smaller particles are referred to us "respirable" particles. The dust collected is called respirable dust. OSHA requires that the way to protect workers from exposure is first by using engineering and work practice controls. If the controls employed are state-of-the art, and the monitoring results show workers are exposed above the TLV/PEL, then the controls must be supplemented with respiratory protection. Infosheets, Sample Forms & Further Information Infosheet 1: Hiring an IH Consultant IH consultant has construction experience (preferable) IH consultant has a supervisory Certified Industrial Hygienist (CIH) (preferable) Sample analyzed by accredited laboratory (necessary) Request sample report Is it well written (do you understand it)? Are results presented as 8-hour time weighted averages? (they should be) Compare costs to those of several other consultants Is the turn-around time for reporting results acceptable? The information gathered from different consultants can be used to choose the best one Infosheet 2: Project Information for the IH Scope of work/silica dust generating tasks Approximate project timetable Approximate number of workers engaged in silica generating tasks Trades and tasks of workers, focusing on dusty tasks Approximate amount of time workers spend on dusty tasks (days/week, hours/day) Location of project and accessibility Description of controls used (engineering, administrative, respirators) Copy of Respiratory Protection Program Details on site safety hazards Site contact person and phone number It is recommended that the SPM have this information ready at hand when speaking with the consultant Checklist: Reporting Results to Workers   Results reviewed then copied to recordkeeping table or spreadsheet   Results copied into form for reporting to workers and dated (Group and Individual reporting form)   Individual results given to monitored workers   Group form posted in area where all workers can view them or Group form handed out to all workers     Sample Recordkeeping Form First Name Last Name Monitoring Date Tasks Results 8-hr TWA (mg/m3) Exceed the TLV/PEL (Y/N) Workers given results (Y/N) Action Taken                                                                                                 AIR MONITORING RESULTS REPORTING FORM (TLV) (Individual) This report presents your results for the for crystalline silica exposure conducted on ___/___/___ Contractor's Name__________________________ Employee name __________________________ Work Site/Location__________________________ Description of engineering /administrative controls at the site______________________________ ______________________________________________________________________________ ______________________________________________________________________________ Job Description __________________________ Monitoring Result __________________________ TLV Exceeded ( TLV = 0.05 mg/m3 ) Yes / No These results represent exposure levels during the time and day the task was performed and the conditions present at the time the monitoring occurred. At this job site _____________________(company name) has selected to use the occupational exposure limit recommended by the American Conference of Governmental Industrial Hygienist (ACGIH). The ACGIH Threshold Limit Value (TLV) of 0.05 mg/m3 is approximately 1/2 the OSHA Permissible Exposure Limit (PEL). The TLV is set at a level below which it is believed that nearly all workers may be exposed to repeatedly over a 40-hour workweek without adverse effect. If exposure exceeds the TLV the appropriate respiratory protection must be used. For more information see attached Silica Facts Sheet. AIR MONITORING RESULTS REPORTING FORM (TLV) (Group) This report presents results for personal air monitoring for crystalline silica dust conducted on ___/___/___ Contractor's Name__________________________ Employee name __________________________ Work Site/Location__________________________ Description of engineering /administrative controls at the site______________________________ ______________________________________________________________________________ ______________________________________________________________________________ Monitor Worker Job Description/ Location Monitoring Results 8-hour TWA mg/m3 TLV Exceeded? Y/N #1       #2       #3       #4       #5       #6       TLV = 0.05 mg/m3 These results represent exposure levels during the time and date the task was performed and the conditions present at the time the monitoring occurred. At this job site ____________________(company name)has selected to use the occupational exposure limit recommended by the American Conference of Governmental Industrial Hygienist (ACGIH). The ACGIH Threshold Limit Value (TLV) of 0.05 mg/m3 is approximately 1/2 the OSHA Permissible Exposure Limit (PEL). The TLV is set at a level below which it is believed that nearly all workers may be exposed to repeatedly over a 40-hour workweek without adverse effect. If exposure exceeds the TLV the appropriate respiratory protection must be used. For more information see attached Silica Facts Sheet. AIR MONITORING RESULTS REPORTING FORM (OSHA PEL) (Individual) This report presents results for personal air monitoring for crystalline silica dust conducted on ___/___/___ Contractor's Name__________________________ Employee name __________________________ Work Site/Location__________________________ Description of engineering /administrative controls at the site______________________________ ______________________________________________________________________________ ______________________________________________________________________________ Job Description __________________________ Monitoring Result __________________________ Exceeded PEL? (Circle one) Yes / No These results represent exposure levels during the time and date the task was performed and the conditions present at the time the monitoring occurred. If exposure exceeds the PEL the appropriate respiratory protection must be used. For more information see attached Understanding the Crystalline Silica Monitoring Report AIR MONITORING RESULTS REPORTING FORM (OSHA PEL) (Group) This report presents results for personal air monitoring for crystalline silica dust conducted on ___/___/___ Contractor's Name__________________________ Employee name __________________________ Work Site/Location__________________________ Description of engineering /administrative controls at the site______________________________ ______________________________________________________________________________ ______________________________________________________________________________ Monitor Worker Job Description/ Location PEL Exceeded? Y/N #1     #2     #3     #4     #5     #6     These results represent exposure levels during the time and date the task was performed and the conditions present at the time the monitoring occurred. If exposure exceeds the PEL the appropriate respiratory protection must be used. For more information see attached Understanding the Crystalline Silica Monitoring Report. Background for Understanding the Crystalline Silica Monitoring Report Monitoring for crystalline silica and interpreting the results needs some explanation. How do we monitor for crystalline silica? A small sampling pump and filter is used to monitor exposure to crystalline silica. When monitoring, only the "respirable" part of the dust is collected, that is, the smallest particles that settle in the lower part of the lungs where silica causes disease. To collect the small particles the filter is attached to a device called a cyclone that separates out the larger non-respirable dust particles. The dust collected on the filter represents only the respirable portion. How does the laboratory analyze the crystalline silica sample? After the sample is collected, it is sent to a laboratory where two analytical procedures are done: The filter is weighed to determine the amount of respirable dust collected. The filter undergoes an X-ray diffraction procedure to determine the percentages of the three most common forms of crystalline silica (quartz, cristobalite and tridymite) in the dust sample. In general the last two don’t show up very often and when they do it is in very small quantities. How is the Permissible Exposure Limit (PEL) for crystalline silica calculated? The PEL for crystalline silica is calculated for each sample taken, using the following equation. Note that this equation combines the percentages of the three most common forms of crystalline silica: quartz, cristobalite and tridymite. PEL for sample = [10 / (% quartz) + (% cristobalite x 2) + (% tridymite x 2) + 2] As an example, consider these numbers: Concentration of respirable sample = 4.8 mg/m3 (weighed in laboratory) % quartz in sample = 10% (from x-ray diffraction analysis) % cristobalite = 1% (from x-ray diffraction analysis) % tridymite = 0.5% (from x-ray diffraction analysis) Calculated PEL for this sample = [10 / (10) + (1 x 2) + (0.5 x 2) + 2] = [10 / (10 + (2) + (1) + 2)] = 10 /15 = 0.66 mg/m3 The PEL is then compared to the respirable dust concentration of the sample: 4.8 mg/m3 / 0.66 mg/m3 = 7.27 Sample concentration is 7.27 times greater than the PEL. This number is the "severity" of exposure. To determine the correct respirator to use we look for a respirator with an Assigned Protection Factor greater then 7.27 The Assigned Protection Factor of a 1/ 2 face Air Purifying Respirator = 10 7.27 is less than 10. Therefore, a 1/2 face Air Purifying Respirator with 100 series cartridges will be acceptable. Silica Facts Silica, also called quartz, is found naturally in the earth's crust. Silica is the basic component of sand and rock. Concrete and masonry products also contain silica. Construction workers may be exposed to silica when working with stone, concrete, brick, or masonry. Activities that can lead to exposure include: Chipping, hammering, and drilling Saw cutting and grinding Crushing, loading, and dumping rock and concrete Abrasive blasting using sand Abrasive blasting on concrete or stone surfaces Dry sweeping What is Silicosis? Silicosis is a disease caused by breathing silica dust. This dust can cause scarring and damage in the lungs. There is no cure for silicosis so prevention is very important. There are several stages of silicosis. Early stages may go unnoticed and can occur after 10 or more years of exposure. The disease can cause fatigue, shortness of breath, loss of appetite, pain in the chest and respiratory failure. Eventually breathing becomes difficult and strains the heart. Some cases of silicosis are fatal. Silicosis causes people to be more susceptible to tuberculosis and bronchitis. Recent scientific information indicates that silica can cause lung cancer. What You Can Do to Protect Yourself Know the health effects of silica and what tasks create silica dust. Use all available controls to reduce dust, like wet methods and vacuums. Participate in air monitoring and training programs. Use a respirator with a P-100 (HEPA) filter for protection against silica dust. Change the filter when it is dirty, damaged, or breathing is difficult. Be clean shaven when you wear a respirator; facial hair interferes with the seal. Employers must provide fit tests every year. When exposures are high, like when abrasive blasting, use airline respirators. Change into disposable or washable work clothes at the worksite. Shower, if possible, and change into clean clothing before going home. Do not eat, drink or use tobacco products in work areas. Wash your hands and face before eating, drinking, smoking, or using lip balm. If you have any questions contact site safety manager___________________________________ Back to Guides for Managing Crystalline Silica Control Programs in Construction This paper appears in the eLCOSH website with the permission of the author and/or copyright holder and may not be reproduced without their consent. eLCOSH is an information clearinghouse. eLCOSH and its sponsors are not responsible for the accuracy of information provided on this web site, nor for its use or misuse. © 2004 by The Mount Sinai — Irving J. Selikoff Center for Occupational and Environmental Medicine eLCOSH | CDC | NIOSH | Site Map | Search | Links | Help | Contact Us | Privacy Policy