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Subchapter 7. General Industry Safety Orders
Group 16. Control of Hazardous Substances
Article 107. Dusts, Fumes, Mists, Vapors and Gases

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Appendix B to Section 5141.1. Protection from Wildfire Smoke Information to Be Provided to Employees (Mandatory)

(a) The health effects of wildfire smoke.
Although there are many hazardous chemicals in wildfire smoke, the main harmful pollutant for people who are not very close to the fire is “particulate matter,” the tiny particles suspended in the air.
Particulate matter can irritate the lungs and cause persistent coughing, phlegm, wheezing, or difficulty breathing. Particulate matter can also cause more serious problems, such as reduced lung function, bronchitis, worsening of asthma, heart failure, and early death.
People over 65 and people who already have heart and lung problems are the most likely to suffer from serious health effects.
The smallest -and usually the most harmful -particulate matter is called PM2.5 because it has a diameter of 2.5 micrometers or smaller.
(b) The right to obtain medical treatment without fear of reprisal.
Employers shall allow employees who show signs of injury or illness due to wildfire smoke exposure to seek medical treatment, and may not punish affected employees for seeking such treatment. Employers shall also have effective provisions made in advance for prompt medical treatment of employees in the event of serious injury or illness caused by wildfire smoke exposure.
(c) How employees can obtain the current Air Quality Index (AQI) for PM2.5.
Various government agencies monitor the air at locations throughout California and report the current AQI for those places. The AQI is a measurement of how polluted the air is. An AQI over 100 is unhealthy for sensitive people and an AQI over 150 is unhealthy for everyone.
Although there are AQIs for several pollutants, Title 8, section 5141.1 only uses the AQI for PM2.5.
The easiest way to find the current and forecasted AQI for PM2.5 is to go to and enter the zip code, town, or city where you will be working. The current AQI is also available at, an interactive map which also provides information about some fires and smoke plumes. You can also visit the website of your local air district. Employees who do not have access to the internet can contact their employer for the current AQI. The EPA website can transmit daily and forecasted AQIs by text or email for particular cities or zip codes.
(d) The requirements of Title 8, section 5141.1.
If employees may be exposed to wildfire smoke, then the employer is required to find out the current AQI applicable to the worksite. If the current AQI for PM2.5 is 151 or more, the employer is required to:
(1) Check the current AQI at the start of each shift and periodically thereafter.
(2) Provide training to employees.
(3) Lower employee exposures.
(4) Provide respirators and encourage their use.
(e) The employer's two-way communication system.
Employers shall alert employees when the air quality is harmful and what protective measures are available to employees.
Employers shall encourage employees to inform their employers if they notice the air quality is getting worse, or if they are suffering from any symptoms due to the air quality, without fear of reprisal.
The employer's communication system is: _____________________
(f) The employer's methods to protect employees from wildfire smoke.
Employers shall take action to protect employees from PM2.5 when the current AQI for PM2.5 is 151 or greater. Examples of protective methods include:
(1) Locating work in enclosed structures or vehicles where the air is filtered.
(2) Changing procedures such as moving workers to a place with a lower current AQI for PM2.5.
(3) Reducing work time in areas with unfiltered air.
(4) Increasing rest time and frequency, and providing a rest area with filtered air.
(5) Reducing the physical intensity of the work to help lower the breathing and heart rates.
The employer's control system at this worksite is: __________
(g) The importance, limitations, and benefits of using a respirator when exposed to wildfire smoke.
Respirators can be an effective way to protect employee health by reducing exposure to wildfire smoke, when they are properly selected and worn. Respirator use can be beneficial even when the AQI for PM2.5 is less than 151, to provide additional protection.
When the current AQI for PM2.5 is 151 or greater, employers shall provide their workers with proper respirators for voluntary use. If the current AQI is greater than 500, respirator use is required, except in emergencies.
A respirator should be used properly and kept clean.
The following precautions shall be taken:
(1) Employers shall select respirators certified for protection against the specific air contaminants at the workplace. Respirators must be certified by NIOSH, the National Institute for Occupational Safety and Health of the U.S. Center for Disease Control and Prevention. A label or statement of certification should appear on the respirator or respirator packaging. It will list what the respirator is designed for (particulates, for example).
Surgical masks or items worn over the nose and mouth such as scarves, T-shirts, and bandannas will not provide protection against wildfire smoke. An N95 filtering facepiece respirator, shown in the image below, is the minimum level of protection for wildfire smoke.
(2) Read and understand the manufacturer's instructions on the respirator's use, care, and replacement, along with any warnings regarding the respirator's limitations. If the respirator is reusable, read and understand the instructions for cleaning and maintenance. The manufacturer's instructions must be followed except for medical evaluations, fit testing, and shaving of facial hair, which are recommended but not required for voluntary use of filtering facepiece respirators.
(3) Do not wear respirators in areas where the air contains contaminants for which the respirator is not designed. A respirator designed to filter particles will not protect employees against gases or vapors, and it will not supply oxygen.
(4) Employees should keep track of their respirator so that they do not mistakenly use someone else's respirator.
(5) Employees who have a heart or lung problem should ask their health care provider before using a respirator.
(h) How to properly put on and use the respirators provided by the employer.
To get the most protection from a respirator, there must be a tight seal around the face. A respirator will provide much less protection if facial hair interferes with the seal. Loose-fitting powered air purifying respirators may be worn by people with facial hair since they do not have seals that are affected by facial hair.
The proper way to put on a respirator depends on the type and model of the respirator.
For those who use an N95 or other filtering facepiece respirator mask that is made of filter material:
(1) Place the mask over the nose and under the chin, with one strap placed below the ears and one strap above.
(2) Pinch the metal part (if there is one) of the respirator over the top of the nose so it fits securely.
Image 1 within Appendix B to Section 5141.1. Protection from Wildfire Smoke Information to Be Provided to Employees (Mandatory)
For a respirator that relies on a tight seal to the face, check how well it seals to the face by following the manufacturer's instructions for user seal checks. Adjust the respirator if air leaks between the seal and the face. The more air leaks under the seal, the less protection the user receives.
Respirator filters should be replaced if they get damaged, deformed, dirty, or difficult to breathe through. Filtering facepiece respirators are disposable respirators that cannot be cleaned or disinfected. A best practice is to replace filtering facepiece respirators at the beginning of each shift.
If you have symptoms such as difficulty breathing, dizziness, or nausea, get medical help immediately.
Note: Authority cited: Section 142.3, Labor Code. Reference: Sections 142.3 and 144.6, Labor Code.
1. New Appendix B filed 7-29-2019 as an emergency; operative 7-29-2019 (Register 2019, No. 31). A Certificate of Compliance must be transmitted to OAL by 1-27-2020 or emergency language will be repealed by operation of law on the following day.
2. New Appendix B refiled 1-16-2020 as an emergency; operative 1-24-2020 pursuant to Government Code section 11346.1(d) (Register 2020, No. 3). A Certificate of Compliance must be transmitted to OAL by 4-23-2020 or emergency language will be repealed by operation of law on the following day.
3. New Appendix B refiled 4-30-2020 as an emergency; operative 6-23-2020 pursuant to Government Code section 11346.1(d) (Register 2020, No. 18). A Certificate of Compliance must be transmitted to OAL by 9-21-2020 or emergency language will be repealed by operation of law on the following day.
4. Emergency filed 4-30-2020 and operative 6-23-2020 extended 60 days pursuant to Executive Order N-40-20 and an additional 60 days pursuant to Executive Order N-66-20. A Certificate of Compliance must be transmitted to OAL by 1-19-2021 or emergency language will be repealed by operation of law on the following day.
5. Certificate of Compliance as to 4-30-2020 order, including amendment of Appendix B, transmitted to OAL 12-17-2020 and filed 2-1-2021; amendments operative 2-1-2021 pursuant to Government Code section 11343.4(b)(3) (Register 2021, No. 6).

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