Disinfectants for swimming pools and spas – be sure to follow the instructions for use

ANSES calls for continued vigilance to avoid accidents when using disinfectant products for swimming pools and spas. The Agency recommends strictly observing the instructions for use and safety precautions, only handling the products outdoors or otherwise in a well-ventilated room, not mixing them together in the same container and storing them away from humidity and heat. These products must also be kept out of the reach of children.   

To enjoy swimming pools and spas safely, it is important to maintain good water quality by using disinfectants. However, these products in their various forms – tablets, balls, pellets, powder or liquid – often contain chlorine and there are risks if used without precautions.

Storing the products

During prolonged storage or in damp conditions, the products can degrade and release toxic vapours when they are opened. When inhaled, these fumes may cause severe irritation of the respiratory tract.

These products need to be stored in a cool place, away from sunlight and humidity, in their original container, which should be closed and placed in an upright position.

In addition, as with all hazardous chemicals, care should be taken not to store them near flammable materials such as solvents or petrol, due to the risk of fire or explosion.

Handling the products

The product should be opened carefully before use, preferably outdoors, taking care not to breathe any vapours that may be released.

If the product needs to be dissolved in water first, it is important to always pour the product into the water and not the other way around to avoid the risk of splashes and burns. Adding water directly to the product can cause an explosive heat-releasing reaction.

Lastly, be careful not to mix chlorination products with other pool products (pH raiser or reducer, bleach, etc.) in the same container. This could cause the release of chlorine fumes, which are highly dangerous gases, or an explosive reaction. To avoid this type of accident, use different, clean and dry measuring cups for each product.

Be sure to follow the recommended doses

Chlorine and bromine products, algaecides, PH raisers and reducers and scale removers are all used for the maintenance of swimming pools and the recommended doses must be followed.

Chlorine concentration in particular should be monitored by regular water testing. Excessively high doses of chlorine can cause irritation of swimmers' eyes, nose or throat, while disproportionately low doses can promote contamination of the water by microorganisms, especially when the pool is used by many swimmers and when the temperature is high.

What to do in the event of an accident?

  • If the product accidentally comes into contact with the eyes, rinse immediately under a stream of lukewarm water while keeping the eyes open for about ten minutes, removing any contact lenses.

    If irritation persists, call your local Poison Control Centre.
  • In the event of prolonged contact with the skin, rinse immediately and thoroughly for about ten minutes.

    If irritation persists, call your local Poison Control Centre.
  • If a person has inhaled fumes, he or she must be taken at once into the fresh air, and placed in a semi-seated position, with the chest slightly inclined.

Call 15 (the health emergencies number for France), or 112 (the European emergency number, from anywhere in the European Union) without delay if the person is experiencing serious breathing difficulties.

If irritation of the respiratory tract persists (e.g. coughing), call your local Poison Control Centre.