Is Mace Legal in Washington State? Carry Rules and Penalties

Mace is legal in Washington State. Any adult can buy, carry, and use pepper spray or mace for self-defense without a permit, a background check, or a license. The governing statute, RCW 9.91.160, sets an age rule but does not cap canister size, chemical concentration, or formulation, and it blocks cities and counties from adding their own bans.¹

Who Can Legally Carry It

Washington’s rule is simple and age-based. If you are 18 or older, you can buy, possess, and carry a personal protection spray device with no further requirements. If you are 14 to 17, you can carry one with written permission from a parent or guardian. Anyone under 14 cannot legally possess pepper spray.¹

That is the whole eligibility test under this statute. Unlike Washington’s firearms laws, RCW 9.91.160 does not bar possession based on felony convictions or prior assault charges. It does say it doesn’t authorize possessing any device or chemical agent that is “otherwise prohibited by state law,” so a separate criminal prohibition could apply in narrow circumstances, but the pepper spray statute itself restricts only by age.¹

No Limit on Size or Strength

Washington doesn’t cap canister volume or the concentration of oleoresin capsicum in the formula. The statute defines a “personal protection spray device” broadly as any commercially available dispensing device designed for self-defense that contains a nonlethal irritant, including tear gas (CN or CS) and pepper-based agents commonly sold as mace or pepper gas.¹ A compact keychain unit and a larger belt canister are both legal.

Where You Can’t Carry It

Washington’s prohibited-places statute, RCW 9.41.300, bans “weapons” from locations like courtrooms, airport security areas, and certain government buildings, but the statute’s weapon definitions center on firearms, explosives, and edged weapons. The courtroom provision lists firearms, explosives, slungshots, sand clubs, metal knuckles, and knives capable of causing death or bodily injury. Pepper spray isn’t in that list.² As a practical matter, courthouses and government buildings with security screening will confiscate a canister at the door regardless of how the statute reads. Assume any building with a checkpoint is off limits.

Federal Buildings

Federal law is broader. Under 18 U.S.C. § 930, possessing a “dangerous weapon” in a federal facility is a crime punishable by up to one year in prison.³ The Interagency Security Committee standard explicitly lists mace, pepper spray, and tear gas among items prohibited in federal buildings.⁴ Federal courthouses, Social Security offices, and VA hospitals all qualify. Leave your spray in the car.

Airports

You cannot bring pepper spray past a TSA checkpoint. You can pack one container of up to 4 fluid ounces in checked luggage if it has a safety mechanism against accidental discharge. Sprays containing more than 2 percent tear gas (CN or CS) by mass are prohibited even in checked bags, and individual airlines may add their own restrictions.⁵

Private Property

Businesses and private property owners can prohibit pepper spray on their premises through a posted sign or verbal notice. Ignoring that notice can get you asked to leave, and refusing to leave can lead to a trespassing charge.

Cities and Counties Can’t Add Their Own Bans

RCW 9.91.160 has a preemption clause. No city, county, or other local government in Washington can prohibit a qualifying person from buying, possessing, or using a personal protection spray device consistent with the state’s self-defense law, and local governments can’t restrict sale or delivery to authorized buyers either.¹ A city ordinance banning pepper spray in a public park, for example, would be unenforceable. The rules in Seattle, Spokane, and a rural county are the same.

When You Can Legally Use It

The statute ties lawful use to Washington’s self-defense law, RCW 9A.16.020. You can deploy pepper spray when you reasonably believe force is necessary to protect yourself or another person from an imminent threat of physical harm. The key word is imminent. Someone yelling at you from across a parking lot is not an imminent physical threat. Someone closing the distance with raised fists and threatening to hurt you is.

The force also has to be proportional. Pepper spray is a low level of force compared to a firearm or knife, which works in your favor against an unarmed attacker. Spraying someone who is walking away, or who no longer poses a danger, crosses from defense into assault. So does using it in anger, as punishment, or in retaliation for something that already happened. Once the threat ends, your legal justification ends with it.

Against Animals

Washington’s self-defense principles are not limited to human threats. If a dog is charging you and you reasonably believe you are about to be bitten, spraying the animal is a proportionate response. Deliberately spraying a restrained or non-threatening animal is a different matter and could expose you to animal cruelty charges.

Penalties for Breaking the Rules

Carrying pepper spray when you are too young and lack parental permission is a misdemeanor under RCW 9.91.160, punishable by up to 90 days in jail and a fine of up to $1,000.¹

Using pepper spray outside the bounds of lawful self-defense is assault. The common charge is assault in the fourth degree, a gross misdemeanor,⁶ which carries up to 364 days in jail and a fine of up to $5,000.⁷ If the spray causes serious injury, or you use it while committing another crime, prosecutors can pursue higher-degree assault charges with felony-level penalties. Using spray during a robbery, for instance, would almost certainly push the charges well beyond a gross misdemeanor.

Ordering or Mailing Pepper Spray

If you are buying pepper spray online or shipping a canister to someone in Washington, the carrier’s rules matter more than state law. The U.S. Postal Service classifies defensive sprays as hazardous irritating materials but allows an exception for products containing oleoresin capsicum, the active ingredient in most pepper sprays. OC-based sprays can be mailed domestically when packaged and labeled according to USPS hazardous materials requirements, including orientation arrows on two sides of the package if the contents exceed 4 ounces. Sprays using CN or CS tear gas as the sole active ingredient are nonmailable through USPS.⁸ Private carriers like UPS and FedEx set their own rules for hazardous materials, so check with the carrier before shipping.

1
Washington State Legislature. RCW 9.91.160 Personal Protection Spray Devices
2
Washington State Legislature. Washington Code 9.41.300 – Weapons Prohibited in Certain Places
3
Office of the Law Revision Counsel. 18 U.S. Code 930 – Possession of Firearms and Dangerous Weapons in Federal Facilities
4
National Archives. Items Prohibited in Federal Facilities – An ISC Standard
5
Transportation Security Administration. Pepper Spray
6
Washington State Legislature. Washington Code 9A.36.041 – Assault in the Fourth Degree
7
Washington State Legislature. RCW 9A.20.021 Maximum Sentences for Crimes
8
Postal Explorer. Publication 52 – Hazardous, Restricted, and Perishable Mail