August 19, 2020

Mr. Jeff Gockel
2 Country Lakes Lane
Waterloo, IL 62298

Dear Mr. Gockel:

Thank you for your letter to the Occupational Safety and Health Administration (OSHA). You requested information on the requirements of OSHA's Respirable Crystalline Silica (RCS) standard for construction, 29 CFR § 1926.1153, as it relates to the use of a leaf blower to remove silica dust from clothing and equipment. This letter constitutes OSHA's interpretation only of the requirements herein, and may not be applicable to any questions not delineated within your original correspondence. Your specific questions are paraphrased below, followed by OSHA's response.

Background: Your letter states that, as a tuckpointer, you work on buildings (e.g, office, residential, hospitals, schools) up to and exceeding 20 stories high. Often, work is done on scaffolds and swing stages that are accessed through windows or from rooftops. Your employer supplies and requires the use of grinders equipped with vacuums to collect silica dust, as well as full-face respirators with appropriate filters. However, you note that some dust escapes the collection system and covers workers and equipment in a heavy layer of dust within minutes. On a regular basis you find it necessary to remove your respirator to communicate with coworkers, clean or defog the respirator during cold weather, and to keep hydrated during extreme heat. In the past, a leaf blower was used to clean a worker’s dust-laden respirator, work clothing, and hardhat for the protection of the worker, as well as to avoid contaminating the interior of the buildings before re-entry from scaffolds.

You found the use of the leaf blower to be a quick and efficient method for removing dust from the nooks and crannies of the respirators, work clothing, and hard hats. The leaf blower occupied little room on the scaffolding or swing stage, and you believe it performed better than other methods, such as using a towel to wipe the dust off. You indicate that you cannot use the vacuum and hose that attaches to the grinder or other power tool because the manufacturer’s instructions warn against using these vacuums to remove dust from the body due to the risk of injury.

Since the implementation of the silica standard prohibits the use of compressed air without a ventilation system where feasible, your employer has unequivocally forbidden the use of the forced air from leaf blowers for cleaning as a means of compliance under the threat of termination.

It is your belief that since the implementation of the silica standard, you and your co-workers cannot effectively remove the dust from your bodies. As such, you consider this a significantly increased health hazard rather than a progression toward elimination of one.

Question 1: Can I use a leaf blower to clean silica dust from my clothes?

Response 1: The standard does not directly prohibit the use of directed or concentrated forced air from leaf blowers to remove silica dust from clothing and PPE. However, the use of a leaf blower to remove silica dust from clothing and personal protective equipment (PPE) may not be the best option because it disperses rather than contains dust, and thus could increase employees’ exposures in many situations. An alternative method of cleaning that your employer could consider is the use of a small HEPA-filtered vacuum that does not pose a risk of injury when operated according to the manufacturer’s instructions.

Question 2: : Is there an OSHA-approved recommendation or control method that an employer should implement to address my specific workplace scenario of removing dust from work clothing and equipment, particularly for workers who work on scaffolding?

Response 2: The construction standard generally allows covered construction employers to select from two methods of compliance to control exposures to respirable crystalline silica: (1) specified exposure control methods¹ or (2) alternative exposure control methods². Under the specified exposure control methods option, employers can comply by fully and properly implementing the engineering controls, work practices, and respiratory protection set forth for the relevant task on “Table 1.” ³ Employers that follow Table 1 do not have to assess employee exposures or separately ensure compliance with the permissible exposure limit (PEL). Table 1 includes 18 common tasks using various types of tools or equipment found at construction sites

For tasks that are not listed on Table 1, or where the employer does not fully and properly implement the engineering controls, work practices, and respiratory protection described on Table 1, the employer must comply with the alternative exposure control methods option, including assessing employee exposures to silica, identifying and implementing feasible engineering and work practice controls to limit exposures to the PEL of 50 µg/m3 averaged over an 8-hour workday, and providing appropriate respirators if feasible engineering and work practice controls do not limit exposures to the PEL.⁴ OSHA expects most construction employers will follow Table 1 because it simplifies compliance and minimizes the burden on employers in many cases.

The use of handheld grinders for mortar removal (i.e., tuckpointing) is listed on Table 1.⁵ Therefore, construction employers have the option of complying with Table 1 for employees engaged in that task, instead of complying with the alternative exposure control methods option. To fully comply with Table 1, the grinder must be equipped with a commercially available shroud and dust collection system and must be operated and maintained in accordance with the manufacturer’s instructions to minimize dust emissions. Table 1 also contains additional requirements related to the dust collection system and its filter and specifies the required respiratory protection and minimum assigned protection factor. The presence of a large quantity of dust (in so short a time) during this operation, according to your letter, could suggest that either (1) the employer is not following Table 1 (and thus should be complying with the alternative exposure control methods option, as discussed above) or (2) that the controls might not be fully and properly implemented.

OSHA’s follow-up interim letter (January 10, 2020) to you, the OSHA Fact Sheet, Control of Silica Dust in Construction, Handheld Grinders for Mortar Removal (Tuckpointing), provides useful recommendations on use and maintenance of grinders.⁶ When excessive dust is generated from equipment, the employer should check that the hose is clear and not filled with debris or kinked, manufacturer’s instructions are being followed to prevent the filter from clogging, and vacuum bags are being changed as needed. Taking steps to assure proper functioning of the equipment might reduce the amount of dust generated and decrease the need to remove excessive dust from clothing and PPE.

You also questioned why OSHA permits indoor dust to be blown outdoors by a window-mounted ventilation fan. Please be aware, whenever OSHA recommends use of an exhaust system (e.g., local exhaust system that captures dust near the source of generation) or a fan to redirect dust from an enclosed space to the outdoors, employers are expected to assess the surroundings and avoid venting into an area where workers would be directly affected. In contrast, it may be somewhat difficult to control the direction of dust blown from a leaf blower while working on a scaffold

In addition, OSHA reminds you that further guidance on proper control methods for silica exposures in construction operations can be found in OSHA’s Small Entity Compliance Guidance for Construction also previously sent to you on January 10, 2020.⁷ This and other guidance materials can be found on OSHA’s Crystalline Silica Safety and Health Topics Page at https://www.osha.gov/dsg/topics/silicacrystalline/construction.html.

Thank you for your interest in occupational safety and health. I hope you find this information helpful. OSHA requirements are set by statute, standards, and regulations. Letters of interpretation do not create new or additional requirements but rather explain these requirements and how they apply to particular circumstances. This letter constitutes OSHA’s interpretation of the requirements discussed. From time to time, letters are affected when the agency updates a standard, a legal decision impacts a standard, or changes in technology affect the interpretation. To assure that you are using the correct information and guidance, please consult OSHA’s website at www.osha.gov. If you have any questions, please feel free to contact the Office of Health Enforcement at (202)693-2190

Sincerely,

Patrick J. Kapust

Acting Director

Directorate of Enforcement Programs