Clean Indoor Air Act Updates - What Montana Businesses Need to Know

What is the Clean Indoor Air Act (CIAA)?

The Montana Clean Indoor Air Act (CIAA), codified under Title 50, Chapter 40, Part 1, MCA, is a state law that protects the public and workers from the harmful effects of secondhand smoke in enclosed public places, including places of work. The CIAA prohibits smoking tobacco, marijuana, and now e-cigarettes (vapes) in enclosed public places.

The purpose of the CIAA is to:

1. protect the public health and welfare by prohibiting smoking in public places and places of employment;
2.  recognize the right of nonsmokers to breathe smoke-free air; and,
3. recognize that the need to breathe smoke-free air has priority over the desire to smoke. § 50-40-102, MCA.

NEW: E-cigarettes Are Now Included in the CIAA

As of May 8, 2025, the CIAA prohibits the use of e-cigarettes in enclosed public places.

• The definition of "smoking" and "to smoke" now includes the use of an "electronic smoking device." § 50-40-103, MCA.
• An "electronic smoking device" is defined as "an e-cigarette, dab rig, or vape pen containing or delivering nicotine or another substance intended for human consumption that can be used by a person in any manner for the purpose of inhaling vapor or aerosol from the product." § 50-40-103, MCA.
• The law applies to "enclosed public places," which are defined as "an indoor area, room, or vehicle that the general public is allowed to enter or that serves as a place of work." § 50-40-103 and 50-40-104, MCA.

What This Means for Your Business

Businesses are required to:

• Prohibit smoking, including the use of e-cigarettes and marijuana, in enclosed public places. § 50-40-104, MCA.
• Post a sign in a conspicuous place at all public entrances to the establishment stating, in a manner that can be easily read and understood, that smoking in the enclosed public place is prohibited. § 50-40-104, MCA.

Free, updated signage is available to order at tobaccofree.mt.gov

Why This Matters

The addition of e-cigarettes into the CIAA helps:

• Protect the public and workers from exposure to harmful chemicals in e-cigarette aerosol. Secondhand aerosol from e-cigarettes can contain nicotine, heavy metals, and other toxins.
• Reinforce healthy social behaviors for youth and young adults.
• Promote cleaner indoor air for everyone.

Compliance & Enforcement

Businesses found in violation of the CIAA will receive an educational letter before the penalties under § 50-40-115, MCA, are applied.

Most violations are resolved with an educational letter. If a business continues to violate the law, the business will receive the following:

1. A written warning for the first violation;
2. A written reprimand for the second violation; and
3. A fine for any third and subsequent violation.

These enforcement actions are based on a rolling 3-year window of non-compliance history for each business.

How to Report a Possible Violation

To report a violation of the CIAA, visit tobaccofree.mt.gov. You can also report a violation by contacting Missoula Public Health's Tobacco Education Specialist.