Pool chlorine + Pool acid
Toxic gases (chlorine)
Never mix chlorine pool products with acid. CDC says this could create toxic gases. [1]
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. [2] [3]
Call 911 for any trouble breathing or swallowing. [2]
Eyes: rinse with lots of room-temperature running water for at least 15 to 20 minutes. [4]
Remove contaminated clothing; wash skin with soap and water. [5] [6] [2]
For mild symptoms or questions, call Poison Help 1-800-222-1222. [2]
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. [6]
Sodium hypochlorite solutions can release dangerous amounts of chlorine or chloramine if mixed with acids or ammonia. [7]
Open one container at a time and close it before opening another. [1]
CAMEO says calcium hypochlorite, used in pool shock, releases highly toxic chlorine gas on contact with acids. [8]
Chemicals
Sources
- CDC — Use Pool Chemicals Safely (poster) 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
- CDC / ATSDR — Calcium Hypochlorite/Sodium Hypochlorite: Medical Management Guidelines retrieved 2026-10-27
- NOAA CAMEO Chemicals — Calcium Hypochlorite retrieved 2026-10-27