Pool shock (calcium hypochlorite) + Glycol-based brake fluid, gasoline, oil
Fire (can ignite after a delay)
Keep pool shock away from glycol-based brake fluid and other garage fluids. Calcium hypochlorite and polyethylene-glycol brake fluid react violently, producing a fierce fireball. [1] [2]
If you already mixed
Leave the area right away and get to fresh air. For household cleaners, open windows and doors to let in fresh air, and stay away until the gas has gone away. [3] [4]
Call 911 for any trouble breathing or swallowing. [3]
Eyes: rinse with lots of room-temperature running water for at least 15 to 20 minutes. [5]
Remove contaminated clothing; wash skin with soap and water. [6] [7] [3]
For mild symptoms or questions, call Poison Help 1-800-222-1222. [3]
A fading smell is not an all-clear: the smell may not be noticeable to people exposed many times, and chlorine gas is heavier than air, so it may linger near the ground. [7]
If they have touched, get away right away. Call 911 immediately if anyone collapses, has trouble breathing or can't be awakened. [8] [9]
Kirkbride and Kobus report that granular swimming pool chlorine (calcium hypochlorite) and polyethylene-glycol brake fluid react violently when mixed, producing a fierce fireball. In their lab tests the mixture lay dormant for between 5 and 30 seconds before erupting into a ball of flame. [1]
CAMEO warns that calcium hypochlorite reactions with alcohols can become violent after a delay; reactions with organic matter or oil may lead to explosions. [8]
OSHA warns that if calcium hypochlorite is not kept dry and is stored with organic or flammable materials, a self-perpetuating fire or explosion could result. [2]
EPA advises keeping combustible or flammable materials away from pool chemicals, particularly gasoline, oil, paint solvents and oily rags. [10]
Chemicals
Sources
- Kirkbride KP & Kobus HJ, Journal of Forensic Sciences 36(3):902-907 (1991) — The Explosive Reaction Between Swimming Pool Chlorine and Brake Fluid retrieved 2026-10-27
- OSHA — Hazard Information Bulletin: Calcium Hypochlorite retrieved 2026-10-27
- Washington Poison Center — Chloramine Gas retrieved 2026-10-27
- Centers for Disease Control and Prevention — Chlorine fact sheet retrieved 2026-10-27
- National Capital Poison Center (Poison Control) — Help for poisons splashed in the eye retrieved 2026-10-27
- NJ Department of Health — Hazardous Substance Fact Sheet: Sodium Hypochlorite retrieved 2026-10-27
- National Capital Poison Center (Poison Control) — Chlorine gas retrieved 2026-10-27
- NOAA CAMEO Chemicals — Calcium Hypochlorite retrieved 2026-10-27
- National Capital Poison Center (Poison Control) — First Aid for Poisonings retrieved 2026-10-27
- U.S. EPA — Chemical Safety Alert: Safe Storage and Handling of Swimming Pool Chemicals (2001) retrieved 2026-10-27