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Press Release State Fire Marshal Reminds Residents about Safe Pool Chemical Handling

Always Mix Pool Chemicals Outside
For immediate release:
  • Department of Fire Services

Media Contact for State Fire Marshal Reminds Residents about Safe Pool Chemical Handling

Jennifer Mieth, Public Information Officer

Pool chemicals

STOWThe warm weather is finally here and people are getting their pools ready for summer fun. State Fire Marshal Peter J. Ostroskey is reminding pool owners to make sure their chemicals are handled and stored properly. “Pool chemicals can be dangerous when they become wet or are mixed with other chemicals,” said State Fire Marshal Ostroskey, “The two most important things to remember are: always mix pool chemicals outdoors; and powder in the water, never water in the powder.”

“Make sure all chemicals are stored in a secure and dry area, and carefully follow all manufacturer’s instructions when using them,” Ostroskey added. “A few simple precautions can be the difference between enjoying a relaxing afternoon by the pool and spending the day in the emergency room,” said Ostroskey. “Call 9-1-1 when you first suspect something is not right and get everyone away from the chemicals to fresh air,” he added.

Last season, local fire departments and state hazardous materials teams responded to several emergencies involving pool chemicals:

  • In June 2020, a Whitman resident caused several minor explosions by mixing two pool chemicals together. The resident sustained minor hearing damage because of the explosions.
  • In July 2020, pool chemicals mixed inside an Agawam home sent two people to the hospital. A very similar incident a few days later in West Bridgewater resulted in another person being transported to the hospital.
  • Last August, a Medway pool owner was mixing pool “shock” in a 5-gallon bucket in her kitchen. The mixture foamed up and overflowed onto the floor. The woman was able to escape the dangerous chlorine vapor but unable to safely clean up the spill.
  • Last fall, a Wareham resident had three 1-pound bags of pool “shock” cause a chemical reaction in his backyard after the chemical got wet.

According to the U.S. Centers for Disease Control, more than 4,000 people nationwide visit the hospital with pool chemical related injuries each year.

Pool Chemical Handling Safety Tips

  • Mix pool chemicals outdoors only in a well-ventilated area.
  • Use gloves, eye protection, and masks as indicated on the packaging.
  • Children should never handle pool chemicals, and even teenagers should not do so without constant adult supervision.
  • Put a lid on chemical containers every time when you are done with them. When containers are left open, water can get in and react with the chemicals. Remember: powder in the water, not water in the powder.
  • Thoroughly clean tools and equipment that were used to handle one chemical before using them with a different chemical.
  • Spilled substances (from damaged containers or accidents) must be cleaned up and disposed of properly to avoid creating an inadvertent chemical reaction.
  • Mixing chemicals can lead to a chemical reaction that may generate temperatures high enough to ignite nearby combustible materials. Mixing can also lead to the release of highly toxic and dangerous chlorine gas.

Pool Chemical Storage

Proper pool chemical storage is important. Pool owners should review how they store their pool chemicals to identify and correct situations where chemicals could be intentionally or accidentally mixed. Make sure to:

  • Separate incompatible substances. The most common pool chemicals are inherently incompatible with each other, so be sure to keep them apart.
  • Avoid storing containers of liquids above containers of powders or other incompatible substances to prevent accidental mixing caused by leaking containers.
  • Avoid mixing old chemicals with fresh chemicals, even if they are the same type.
  • Use separate, designated scoops for each chemical. Handle only one chemical at a time and make sure that tools used with one substance are not used with another unless all residues are removed.
  • Use separate, designated containers for cleanup of spilled materials to avoid inadvertent mixing of spilled substances. Consult your local hazardous waste disposal facility for more detailed information on proper waste disposal.
  • Store pool chemicals outside the home or attached garage. A locked stand-alone shed is recommended.
  • Lock your storage area to keep children, pets and unauthorized users out.
  • Keep your storage area free of rags, trash, debris, or other materials that could clutter the area. Keep combustible and flammable substances away from the area.

Proper Chemical Disposal
Do not dispose of old pool chemicals in the trash or down the drain. Take old chemicals to a household hazardous waste collection day in your community or to a commercial hazardous waste facility. Since sodium hypochlorite (bleach) is the same chemical used in most water treatment facilities, check to see if your local plant will accept the chemical.

For more information about how to store and use pool chemicals safely, consult the following organizations:

U.S. Centers for Disease Control

Massachusetts Department of Environmental Protection

U.S. Environmental Protection Agency



Media Contact for State Fire Marshal Reminds Residents about Safe Pool Chemical Handling

Department of Fire Services 

The Department of Fire Services helps keep communities safe. We provide firefighter training, public education, fire prevention, code enforcement, licensing, fire investigation, hazardous material response, and emergency response.
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