Using Pool Chemicals Safely

The Events

Recently, many staff members have been injured while handling pool chemicals. Most of these incidents involved granular chlorine, but tablets and liquid forms were also involved. Other events involved cleaning with known and unknown chemicals.

Fortunately for those involved, none of the outcomes were as serious as they could have been. Irreparable damage to lungs and/or eyes could easily have been the outcome. All of the incidents were during routine, frequently done tasks:

  • Opening a bucket of granular chlorine (most common)
  • Cleaning (though sometimes with an unknown cleaner)
  • Untangling chlorine supply lines
  • Emptying trash
  • Using pool chemical testing materials

The Possibilities

Gaseous chlorine (CL2) is an extreme irritant that can cause serious tissue damage – it combines with moisture in the respiratory tract, mucous membranes, or eyes to form hydrochloric acid. Just 15 parts per million (ppm) will immediately irritate the throat; a short exposure to 50 ppm is dangerous; to 1,000 ppm it can be fatal.

  • Most organizations do not utilize chlorine gas directly, but it will be released from granular or solid tablet chlorine compounds that are exposed to moisture. Should that exposure happen inside a closed container, opening the lid may release a significant concentration of chlorine gas.
  • Using muriatic (hydrochloric) acid to clean the grate on which chlorine-compound tablets sit inside the chlorinator will produce chlorine gas. This can be problematic if done in a confined space or if the gas is released suddenly because the lid was in place.

Granular or Tablet Chlorine
(often calcium hypochlorite)
This has dust that is highly caustic to mucous membranes and eyes. Hydrochloric acid forms when the dust interacts with the moisture present in eye or respiratory tissues with results similar to those above. Just opening the container created enough airflow to blow this caustic dust into the eyes of some of those recently injured.

Liquid Chlorine
(generally sodium hypochlorite)
This is an irritant that can do damage similar to that caused by dust or gaseous chlorine compounds, though generally not as disastrous because it is usually in 10-12% (pool chemicals) or 4-6% (household bleach) concentrations. Though not necessarily life-changing, such injuries are still painful.

Unlabeled Containers
These are an OSHA violation – statutes require all containers to be clearly labeled unless used by a single individual during a continuous work period and disposed of immediately thereafter. Unlabeled containers should be opened only with appropriate respiratory and eye protection and disposed of promptly and properly. Simply opening an unlabeled container can cause harm as several of our claimants have learned.


The Lessons

Chlorine products are hazardous – they should never be treated casually. Safety Data Sheets (SDS) for all of these chemicals specify the use of personal protective equipment (PPE), yet none of those whose incidents triggered this alert used appropriate PPE. All employees should be trained according to your Hazard Communication Policy.

  • Opening the lid to a container of granular or pellet chlorine without a full face respirator or a respirator and goggles is gambling your eyes and possibly your life. There are no guarantees that moisture did not get into the container and produce caustic gas or that air movement will not blow caustic dust into your eyes.
  • Cleaning the grate of a pellet dispenser without like protection is similarly betting that the generated Cl2 will not collect, rapidly release, or be inadequately dissipated in the area in which you are working.
  • Any handling or use of granulated or pellet chlorine should include goggles and gloves – air movement from any source can blow caustic dust into your eyes.
  • Any use of muriatic (hydrochloric) acid should utilize goggles, gloves, and apron; using it to clean an item of chlorine-related build-up requires a respirator as well.
  • Any activity involving liquid chlorine: cleaning, pouring fluid, switching supply lines, moving sealed containers, etc. – should only be done while wearing goggles; the use of gloves is also highly advisable.
  • Goggles cannot safely be replaced by safety glasses and/or a face shield – splashes often go underneath or around these devices, as our incident reports verify.
  • An unlabeled container should be treated as garbage. Do not open it and do not try to use the material in it. Neutralize or destroy it in a well ventilated space using appropriate protocols and PPE.

Pool chemicals are common and thus often treated as harmless – they are not! Always use the appropriate PPE. Be prepared for the unexpected, not devastated by it.