blue line

Occupational Exposure to Secondhand Marijuana Smoke

Cannabis, EH&S News, Health & Safety Training, Industrial Hygiene

Written by: Zohreh Saadati, NES, Inc.

Occupational Exposure to Secondhand Marijuana SmokeWith more employees working in legal marijuana industry facilities, occupational exposure to secondhand marijuana smoke is becoming a heated issue.


Secondhand Marijuana Smoke Discussed by Cal/OSHA

In a September 9, 2018 memorandum the California Occupational Safety and Health Administration (Cal/OSHA) summarized a January marijuana advisory meeting in which the risk for exposure to secondhand marijuana smoke and other marijuana-related workplace hazards were considered. The California Labor Code requires Cal/OSHA to conduct such meetings whenever the potential need to develop new industry-specific regulations is identified, and the legalization and legitimization of the marijuana industry in California presented this type of case.

The main impetus for the meeting was to investigate any overlap or applicability of existing regulations prohibiting the smoking of tobacco products in many workplaces and adjacent locations as outlined in California Code of Regulations, Title 8, §5148 (8 CCR 5148). In addition to occupational secondhand marijuana smoke exposure, potential risks including combustion, inhalation of hazardous substances, armed robbery, musculoskeletal issues, repetitive strain injuries, and exposure to bacteria, endotoxins, and/or fungi were addressed.

To learn more about the hazards that can be encountered in marijuana industry facilities, read the April 2018 NES blog post Marijuana Industry Hazards.


Secondhand Marijuana Smoke Exposure Arguments

The January meeting involved the input of various industry stakeholders, legal representatives, labor unions, occupational health and safety experts, consultants, and government representatives from outside of Cal/OSHA. Arguments mainly revolved around updating, and expanding the purview of, existing tobacco smoking regulations under 8 CCR 5148 to apply to the marijuana industry.

The Argument for Expansion of 8 CCR 5148

The Tobacco Education and Research Oversight Committee (TEROC) submitted a written statement following the January 2018 meeting outlining the overlap between the hazardous compounds found in tobacco smoke and those detected in marijuana smoke. According to TEROC, “Cannabis secondhand smoke contains many of the same chemicals and carcinogens as tobacco secondhand smoke; contains tar, ammonia, and hydrogen cyanide at higher levels than in tobacco secondhand smoke.” TEROC also recommended that 8 CCR 5148 amend the definition of “enclosed space” to include covered parking lots.

This argument was echoed and furthered in comments issued by the national non-profit public health organization Americans for Nonsmokers’ Rights (ANR). ANR expressed deep concern that secondhand marijuana smoke exposure was believed by some to be sufficiently combated by ventilation engineering controls, stating the “American Society for Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE), the standard setting body for the HVAC industry, affirms that mechanical solutions like ventilation and other air cleaning technologies cannot control for the health hazards of secondhand smoke.” Other control measures deemed ineffective were HVAC systems, carbon filters, negative ion generators, worker rotation to mitigate exposure, and staff training.


Occupational Secondhand Marijuana Smoke Exposure More CommonThe availability of legal marijuana smoke shops in California is increasing, but where should the regulations fall on incidental occupational exposure to marijuana smoke?


Arguments Beyond Secondhand Marijuana Smoke Exposure

Beyond the argument on secondhand marijuana smoke exposure, the United Food & Commercial Workers Union (UFCW) Western States Council, which represents over 1,500 marijuana workers in Los Angeles County and beyond, submitted written comments regarding various additional workplace elements germane to the marijuana industry. Among them, UFCW requested Cal/OSHA to promulgate rules specific to violence in the industry, stating that “Banking issues, patient psychological needs, and black market enterprises leave the cannabis industry vulnerable to acts of violence in the workplace” and arguing that the regulations that might best fit the marijuana industry would be those applied to health care workplaces, which mandate that “an employer’s Workplace Violence and Prevention Plan contain procedures for obtaining assistance from law enforcement, procedures to identify and evaluation patient-specific risk factors and assess visitors or other persons who are not employees.”

For more information on regulations concerning workplace violence in health care settings, view the September 2018 NES article Preventing Violence in Health Care Workplaces.

UFCW also suggested that Cal/OSHA require that, within one year of receiving a license, one marijuana industry supervisor and one employee complete a Cal/OSHA General Industry 30-Hour training course conducted by an OSHA-authorized training provider. In essence, the argument for needing this training, at least while the industry is young and maturing, is that to adequately manage the potential hazards/risks would require more sophistication than is currently typically present in-house for the smaller organizations that comprise most of the industry.

Concurring with secondhand marijuana smoke, workplace violence, and Cal/OSHA General Industry 30-Hour training requirement arguments was Worksafe, an occupational health and safety non-profit organization that advocates on behalf of California workers. Worksafe’s written statement emphasized the lack of pertinent data on working conditions and difficulty in knowing the long-term effects of exposure to marijuana, given that the burgeoning industry had very recently existed as an illicit market.

See March 2018 NES article Marijuana Industry Health and Safety: The Next Step to Legitimacy for a breakdown of health and safety training currently lacking in the marijuana industry.

Other topics included the risk of combustion and repetitive strain injuries. Exposure to non-marijuana-based airborne contaminants was discussed as well. Some employees experience itchiness, rashes, skin irritation, and mild allergic reactions when exposed to marijuana, symptoms that may be attributed to trichomes present on the plant. Suggested control measures for these hazards included personal protective equipment (PPE), puncture-proof gloves, respirators, and goggles. Employees would benefit from training on the proper use of these options.


Cal/OSHA’s Conclusions

The September 2018 Cal/OSHA memorandum concluded by expressing the agency’s intent to “propose that the Standards Board undertake rulemaking to amend title 8 section 5148 to prohibit the smoking of marijuana in enclosed spaces of places of employment” and “assist in the rulemaking effort.” Cal/OSHA agreed that hazards beyond occupational marijuana smoke exposure are relevant, but noted that marijuana industry employers are already required to attend to these concerns under existing regulations. Therefore, regulations specific to the marijuana industry were not deemed to be needed at this time.


NES Marijuana Hazards Safety Training for Regulators

NES has developed training specific to regulators who will have to work in and around marijuana industry operations in the course of their job duties. This training is offered on-site and in open enrollment format as Marijuana Grow Hazards Safety Training for Regulators and covers topics such as Proposition 64, physical hazards, chemical hazards (including pesticides), biological hazards (including mold), lighting hazards, air monitoring, PPE, and toxicology. For more information on NES’ marijuana training, please contact us at 916-353-2360 / 800-637-2384 or email us at



Cal/OSHA Memorandum: Cal/OSHA Advisory Committee Findings and Recommendations on the Need to Develop Industry-Specific Regulations for Marijuana (Cannabis) Establishments

8 CCR 5148: Prohibition of Smoking in the Workplace

TEROC Written Statement

ANR Comment on Proposed Cannabis Regulations

UFCW Cannabis Industry Cal/OSHA Regulations Comments

Worksafe Written Statement