Cultured Stone
EZ Scaffold Corp.
EZG Manufacturing
Federated Insurance
Fraco USA, Inc.
Hydro Mobile, Inc.
Kennison Forest Products, Inc.
Mortar Net Solutions
Non-Stop Scaffolding
Norton Clipper
Southwest Scaffolding
The Belden Brick Company
Xtreme Manufacturing

Silica Questions and Answers

The Occupational Safety and Health Administration (“OSHA”) has released a set of 53 Frequently Asked Questions (“FAQs”) to provide guidance to employers and employees regarding OSHA’s respirable crystalline silica standard for construction. Through the Construction Industry Safety Coalition (“CISC”), Mason Contractors Association of America was involved in the formulation of these FAQs.

The development of the FAQs stemmed from litigation filed against OSHA by numerous construction industry trade associations challenging the legality of OSHA’s rule. OSHA has also agreed to issue a Request for Information (“RFI”) on Table 1 to revise the Table to improve its utility. Mason Contractors Association of America will continue to look for ways to work with OSHA to improve the workability of this significant rule.

The FAQs are extensive and organized by topic. A short introductory paragraph is included for each group of questions and answers to provide background information about the underlying regulatory requirements. While employers are encouraged to review all of the FAQs, the following are some of the clarifications provided in the document.


The standard applies to all occupational exposures to respirable crystalline silica in construction work, except where employee exposures will remain below an Action Level (“AL”) of 25 µg/m3, calculated as an 8-hour time weighted average (“TWA”), under any foreseeable conditions. The exception is intended to ensure that the standard does not apply to employees whose work results in only minimal silica exposures.

The FAQs clarify that many common construction tasks are likely to be outside the scope of the standard because they typically generate exposures below the AL. This includes mixing small amounts of mortar; mixing small amounts of concrete; mixing bagged, silica-free drywall compound; mixing bagged exterior insulation finishing system base and finish coat; and removing concrete formwork. In addition, tasks where employees are working with silica-containing products that are, and are intended to be, handled while wet, are likely to generate exposures below the AL (examples include finishing and hand wiping block walls to remove excess wet mortar, pouring concrete, and grouting floor and wall tiles). The FAQs also state that many silica-generating tasks performed for only 15 minutes or less a day will fall outside the scope of the standard.

Table 1

The standard permits employers to select from two methods of compliance to control exposures to respirable crystalline silica: “specified exposure control methods” commonly referred to as Table 1 or “alternative exposure control methods.” Employers that follow Table 1 do not have to assess employee exposures or separately ensure compliance with the permissible exposure limit. Table 1 includes common construction tasks.

The FAQs clarify that the Table 1 requirement that employers “operate and maintain” tools “in accordance with manufacturer’s instructions to minimize dust emissions,” applies only to manufacturer instructions that are related to dust control. Other information in these instructions, including recommended respiratory protection, do not have to be followed for purposes of the standard.

For a few tasks on Table 1, respirator requirements vary based on task duration, i.e., whether the task is performed for “less than or equal to four hours/shift” or “greater than four hours/shift.” The FAQs make clear that an employer does not have to track the exact amount of time that employees are performing a job throughout a shift to be in compliance with Table 1. Rather, before a task is performed, an employer must make a good-faith judgment about whether the task will take more than four hours. If the employer anticipates that an employee will be engaged in a task for more than four hours, the employer must provide the employee, at the beginning of the shift, the respiratory protection required in the “greater than four hours/shift” column on Table 1. If, in contrast, the employer anticipates that an employee will be engaged in a task for four hours or less, the employer needs to provide respiratory protection in accordance with the “less than or equal to four hours/shift” column. Finally, the FAQs clarify that handheld powered demolition hammers with bushing tools and tile saws are covered by Table 1.


The standard includes requirements related to housekeeping on construction worksites. In particular, employers must not allow dry sweeping or dry brushing “where such activity could contribute to employee exposure to respirable crystalline silica unless wet sweeping, HEPA-filtered vacuuming or other methods that minimize the likelihood of exposure are not feasible.” In addition, employers must not allow compressed air to be used to clean clothing or surfaces where such activity could contribute to employee exposure to respirable crystalline silica unless: (1) the compressed air is used in conjunction with a ventilation system that effectively captures the dust cloud created by the compressed air, or (2) no alternative method is feasible.

The FAQs clarify that if employee exposure will remain below the AL under any foreseeable conditions, the prohibition on dry sweeping, dry brushing, and the use of compressed air for cleaning clothing and surfaces does not apply. They also clarify that the prohibition on these activities only apply to housekeeping activities, not to the use of these practices to perform a work task.

Written Exposure Control Program

The standard requires employers to establish and implement a written exposure control plan that contains at least the following elements: (1) a description of the tasks in the workplace that involve exposure to silica; (2) a description of the engineering controls, work practices, and respiratory protection used to limit employee exposure to silica for each task; (3) a description of the housekeeping measures used to limit employee exposure to silica; and (4) a description of the procedures used to restrict access to work areas, when necessary, to minimize the number of employees exposed to silica and their level of exposure, including exposures generated by other employers or sole proprietors.

The FAQs clarify that the standard does not require employers to develop a new written plan for each job or worksite. It requires only that employers have a written exposure control plan applicable to each worksite. Employers may develop a single comprehensive written exposure control plan that covers all required aspects of the plan for all work activities at all worksites. The FAQs also clarify that when silica generating tasks are being performed, the standard is not intended to prohibit all employees from entering entire areas of a construction site simply because employees in those areas are performing some work involving the generation of silica. The rule calls only for minimizing the number of employees in the relevant work areas. The standard does not preclude employees from entering work areas where silica-generating tasks are occurring when it is necessary for them to do so.

Medical Surveillance

The standard requires construction employers to make medical surveillance available at no cost, and at a reasonable time and place, to any employee who is required by the silica standard to use a respirator for 30 or more days a year. An initial examination must be offered within 30 days of initial assignment, unless the employee has received a medical examination that meets the requirements of the standard within the last three years.

The employee will receive a written medical report within 30 days of each exam that includes: (1) a statement indicating the results of the medical examination; (2) any recommended limitations on the employee’s use of respirators; (3) any recommended limitations on the employee’s exposure to silica; and (4) a statement, if applicable, that the employee should be examined by a specialist. The employer must also obtain a written medical opinion within 30 days of each exam, which contains more limited information than the report to the employee. The opinion to the employer contains the date of the examination, a statement that the examination has met the requirements of the standard, and any recommended limitations on the employee’s use of respirators.

The FAQs make some important clarifications regarding medical surveillance. The silica standard does not preclude in-house health care providers from performing the required medical surveillance examinations. In addition, the standard does not preclude employers from receiving the same information that employees receive from the surveillance examination, if it is received for other purposes and through other means, such as through workers compensation records and proceedings. The FAQs also make clear that the standard requires employers to make medical surveillance available to qualifying employees, but does not require that employees participate in the surveillance.

Additional Information Provided by the MCAA

What can I do to make sure I comply with these three?

Make sure you register for the MCAA's Silica Train-the-Trainer Course. It is currently running in cities around the country and more are being regularly added. When you send someone from your company, they will be equipped to come back to the office and train your entire staff. They will have programs to do the one hour program and the six hour competent program for your foremen.

The course for MCAA members is very inexpensive given the resources you will have to train your staff. Member pricing is only $350 per person. As an MCAA member you will have access to a free written program. Members are now able to log in online and get a custom written program. After login, the program will auto populate your company information into the program. You will need to load tasks and specifics to your specific job and then be able to print it out for use on your site. The program will be updated on our site as the rule changes so your program will always be compliant.

Non-members may participate in the training as well. The fee is $700 per person. The written program is not currently available to non-members. Non-members may join at the time of their registration for the class for an additional $150 which would make them a member of the MCAA through June 2018. Then they would have access to the written plan as well.

What happens after I train my people back home?

You will have a test each person will take to show they took the training. You should retain the test for your records. Submit the people who were trained, both the 1 hour basic training and the 6 hour competent trained people to the MCAA (a form is available online). We will register them in our master database, you will be sent a certificate and card for each person that completed the program. In our database we will track when the training occurred and when it should be renewed. There is a $15 per person processing fee for this service. This will provide the credibility of the course taught that you need for those OSHA inspections.

Can the employee training be done by a means other than live?

Yes, the employer can decide the best method for the training so video is okay (assuming it is specific to the work of the employer). The employee must have an opportunity to ask questions of someone after the video/webinar. The employer also must be demonstrate that the employee has knowledge and understanding of the training too – so the written quiz is a good idea – although orally discussing the training with the employee would be okay too.

Can my written plan be paperless on the job-site like my other documents?

Yes, it can. However, it must be available to employees for access and it must have been reviewed with employees.

What is a APF 10 repirator?

The respirator standard provides the APF in Table 1 (see below) based on the size and type of respirator. The attached pages provide a visual cue for the APF for the type of respirator. A N-95 filtering respirator is air-purifying and is considered half-mask so it has an APF of 10.

Download a PDF for graphic examples of the respirators.

If we offer APF masks on a voluntary basis would that count towards the medical surveillance required in the rule if worn more than 30 days in a year?

Medical surveillance is only triggered if the employee is required to wear a respirator for 30 days or more either under Table 1 or because exposure is at or over the PEL. So, voluntary use of respirators should not trigger the medical surveillance requirement. However, employer must apply the voluntary use provisions of the respiratory protection standard.

Can we utilize air monitoring of others for our job site?

Under the performance option, the employer can assess employee exposure to silica on the basis of any combination of air monitoring data or objective data sufficient to accurately characterize employee exposures to respirable crystalline silica. Objective data means information, such as air monitoring data from industry-wide surveys or calculations based on the composition of a substance, demonstrating employee exposure to respirable crystalline silica associated with a particular product or material or a specific process, task, or activity. The data must reflect workplace conditions closely resembling or with a higher exposure potential than the processes, types of material, control methods, work practices, and environmental conditions in the employer's current operations. Any objective data relied upon must be maintained.

To accurately characterize employee exposures under the performance option, the assessment must reflect the exposures of employees on each shift, for each job classification, in each work area. Accurately characterizing employee exposures under the performance option is also an ongoing duty. In order for exposures to continue to be accurately characterized, the employer is required to reassess exposures whenever a change in production, process, control equipment, personnel, or work practices may reasonably be expected to result in new or additional exposures at or above the action level, or when the employer has any reason to believe that new or additional exposures at or above the action level have occurred.

When using the performance option, the burden is on the employer to demonstrate that the data accurately characterize employee exposure. However, the employer can characterize employee exposure within a range, in order to account for variability in exposures.

OSHA indicated in the preamble to the Final Rule that OSHA intends for the performance option to give employers flexibility to accurately characterize exposures using whatever processes or data are most appropriate for their circumstances. Some examples that could generate objective data include:

  • area samplings
  • historic air monitorings
  • area exposure profile mappings
  • real-time monitorings
  • analysis of bulk samples or safety data sheetss
  • data from less than full-shift samples where professional judgment can be used to determine exposure levelss
  • published scientific reports in the open scientific literatures
  • NIOSH health hazard evaluationss
  • insurance carriers’ loss prevention reportss
  • industry-wide datas
  • safety data sheets from product manufacturerss
  • prior historical sampling data under comparable conditionss
  • aggregated company-wide sampling information as reliable sources of objective datas
  • data collected by a trade association from its members

Where employers rely on objective data generated by others as an alternative to developing their own air monitoring data, they will be responsible for ensuring that the data relied upon from other sources are accurate measures of their employees’ exposures. Thus, the burden is on the employer to show that the exposure assessment is sufficient to accurately characterize employee exposures to respirable crystalline silica.

So, employers can team together and use data from another if the source is an accurate measure of their employees’ exposure. To be an accurate measurement, it would likely need to be a task that would generate the same or similar exposure. State testing could meet this criteria assuming that the working conditions, environment and product are similar enough that it would reasonable to use those results to characterize employee exposure. I would recommend having several samples (versus one) to demonstrate that the results would be accurate and similar. Moreover, testing information from industry trade groups and manufacturers can be used by employers if there are similarities in tasks and products that they could be used as an accurate measure of their employees’ exposure.

Do I have to re-train employees?

Yes re-training is required. As defined in the rule:

Employees must be trained at the time they are assigned to a position involving exposure to respirable crystalline silica. Additional training must be provided as often as necessary to ensure that employees know and understand respirable crystalline silica hazards and the protections available:
  • Employee is assigned a new task.
  • Employer introduces new protections/controls.
  • When an employee is working in a manner that suggests he or she has forgotten what was learned in training.

Our recommendation is to re-train employees and competent people every year and trainers need to be re-trained every two years. We would consider that schedule to be reasonable.

For further questions, please contact the Mason Contractors Association of America at 800-536-2225 or visit

“The MCAA is perfectly suited to provide webinars and other training resources.”

Todd Witmer
The Witmer Group
MCAA member since 1995

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