PackSafe - Sprays and Repellents
Animal Spray, Repellent
Greater than 118 ml (4 fluid ounces), bear spray, animal repellent
See "Self-defense spray" in this table for an exception for checked baggage for certain sprays not exceeding 118 ml (4 fluid ounces). Most bear sprays are beyond the 4-ounce size and therefore cannot be carried.
Mosquito, Insect Repellent
Quantity limits: Included in, not in addition to, the quantity limits for other medicinal and toiletry articles: The total aggregate quantity per person cannot exceed 2 kg (70 ounces) or 2 L (68 fluid ounces). The capacity of each container must not exceed 0.5 kg (18 ounces) or 500 ml (17 fluid ounces).*
Aerosol release devices (button/nozzle) must be protected with a cap or other means to protect against accidental release.
This exception is for repellents that are sprayed/applied directly on a person's skin and clothing and as such are included in the exception for medicinal and toiletry articles. Insect repellents or insecticides designed to be sprayed in the air or at the insect are not included in this exception.
See the regulation: 49 CFR 175.10(a)(1)
Tip: Most insect repellents in non-aerosol liquid pump sprays and other forms (liquids, lotions, wipes, etc.) are not restricted as hazardous materials — and therefore not subject to size or quantity limits. Some liquid repellents, including some containing Picaridin, are flammable liquids--these are still allowed but must stay within the size and quantity limits mentioned above.
*Liquids, gels, and aerosols in carry-on baggage are further limited to 100-ml (3.4 oz) containers at the TSA security checkpoint.
Self Defense Spray
Mace, pepper spray not exceeding 118 ml (4 fluid ounces)
Quantity limitations: One self defense spray, not exceeding 118 ml (4 fluid ounces), per passenger in checked baggage only.
Self defense sprays containing more than 2% by mass of tear gas (CS or CN) are prohibited.
The device and ingredients must meet the specifications of a self-defense spray as described in 49 CFR 171.8.
The device must include a positive means to prevent accidental discharge (a recessed button can't be the only safety feature; there must be an addition device such as a cap that flips up).
See the regulation: 49 CFR 175.10(a)(9)
Important note: International aviation regulations (ICAO/IATA) prohibit self-defense sprays in both carry-on and checked baggage.