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Sep 30, 2015
Services: Civil Litigation

Public Pool Mishaps


Legal issues and concerns involving chlorine spills and accidents

 By Donald G. Kidd, BA, LLB

“The gas hit me like a ton of bricks. I couldn’t breathe,” said Donald MacLenna after a dangerous chlorine accident at St. Catherines, Ont.’s Lion Dunc Pool in 2012. Bathers were enjoying the pool when a worker accidently poured 90 L (23.7 gal) of chlorine into a tank containing muriatic acid.

This produced a toxic gas cloud that filled the pool area and was seen billowing out of windows and doors. The toxic spill affected 180 people, sent 12 to hospital, and resulted in a $10-million class action lawsuit against the City of St. Catherines and the company that serviced the pool.1,2 This is a clear example of the legal backlash pool operators and companies can face in response to a chlorine accident.

The aquatics industry needs to protect itself from liability during all stages of chemical handling as the industry’s reliance on chlorine poses unique challenges. This article will outline the necessary steps aquatic industry members should consider to shield themselves against claims from workers and/or the public with regards to chemical-related accidents.


Being the target of a lawsuit after a chlorine accident can be financially disastrous; therefore, it makes economic sense to protect workers and the public within reasonable costs considerations.

When a chemical accident happens, pool companies can face heavy fines from the province along with civil lawsuits from everyone who was affected. Pool companies should have written safety protocols and procedures for dealing with chlorine and other pool chemicals. If an accident occurs, the pool company and/or facility operator may need to show a judge every reasonable step expected and in place by the aquatics industry was taken to protect against harm from the use of chlorine and/or other chemicals.

Chlorine’s effect as a gas can range from mild to severe, depending on exposure levels. It can cause mild breathing problems and skin rashes to severe chemical burns, pulmonary edema, and death. When an injury occurs to an employee, the Workplace Safety and Insurance Board (WSIB) becomes involved and members of the public can sue for the harm done to them physically, mentally, emotionally, and financially. Owners, managers, supervisors, and workers all have a duty to be safe and take all reasonable precautions to protect themselves and others who could be exposed. 


The Occupational Health and Safety Act3 states an employer must take every precaution, reasonable in the circumstances, to protect a worker. This means taking all the necessary steps to prevent a foreseeable accident.

A foreseeable accident is one that a reasonable person would consider to be possible in all of the circumstances. The operator/company is obliged to proactively protect all of those who could be exposed to chlorine gas. Whenever chemicals are involved, foreseeable accidents can include some of the absolute worst outcomes, including explosions, gas leaks, emergency evacuations, chemical burns, and death.

Protecting against liability claims begins as soon as workers come into contact with or are using chlorine; whether it is transporting canisters of chlorine gas into the pool’s storage area, inputting chlorine into the pool system, or disposing of used containers and solution. It is very important every worker handling chlorine is properly trained in the correct procedures.

A waiver is never satisfactory as it has to be properly worded and has to be brought to the attention of the person signing, which rarely ever happens.  


The definition of ‘worker’ includes everyone contracted by the pool company to perform work, whether they receive a regular paycheque or take home cash at the end of the day. The law defines a ‘worker’ very broadly.  Pool companies must also be careful to protect high school students working during the summer or in co-op programs.

Pool chlorination systems often require routine maintenance and inspection by pool company workers; however, third-party workers may operate and maintain the system in-between the work performed by pool company employees. Pool companies need to ensure third parties using the system are being responsible, and the pool system is functioning properly for their use.


Employers must provide proper personal protective equipment (PPE) for workers around chlorine. The PPE will depend on the type of chlorine application and the worker’s duties. The law mandates the strictest PPE requirements for gas chlorination systems, but all chlorine handling requires some level of protection.

When it comes to gas chlorinators, employers are obligated to provide full-face, self-contained, air-supplied breathing equipment. The breathing equipment must allow a person to withstand 15 minutes in a chlorine-filled environment and be kept in a dust-proof cabinet outside a possible chlorine contamination area. In the event that someone is trapped in a chlorine contaminated area, breathing equipment provides a better chance of survival and is mandated by law. Breathing equipment also provides more time for trained personnel to rescue victims.

Granulated and liquid chlorine applications have different PPE requirements. The employer must provide safety goggles to protect a worker’s eyes from chemical splashes and dust, and chemical-proof gloves and aprons to protect the worker’s skin and body.

In the aftermath of an accident, the pool company will need to show that functional PPE was readily available to the workers and they were properly trained to use it. Even minor chlorine contact, such as a worker using their bare hands to toss chlorine pucks into the pool, could create liability for the employer. Long-term contact with chlorine can cause chloracne, a form of dermatitis. Pool companies do not want a worker developing these preventable conditions and suing years later for failing to provide gloves. 


The law also requires that only properly trained workers operate chlorination equipment. Workers need to have ongoing training and reinforcement to show they are following the rules and observing best practices. Employee training is not a one-time affair. Proper training is part of an employer’s due diligence; in the event of a worker accidently mixing improper chemicals, courts will look to the employer to determine what standards the worker was held to and the rules they were instructed to follow.

Material safety data sheets (MSDS) must be provided to workers and be easily accessible. These documents highlight the safety precautions required around each chemical, the correct PPE to wear, and first aid measures.

The employer has a duty to regularly monitor and supervise an employee’s work to ensure they are following proper chlorine handling practices. Workers can take shortcuts and, over time, they can become accepted practices. From a legal standpoint, safety shortcuts are unacceptable and, in the context of a lawsuit, could be seen as carelessness that makes the operator/company liable for the claims made against it.

In the workplace, the employer should foster a culture of safety and respect for chlorine and other pool chemicals. Pool workers need to understand the consequences of mishandling chlorine. If workers are aware of the potential harm from taking safety shortcuts, it is harder for them to justify taking the shortcut in the event of an accident. 


The law further imposes standards for pool chlorine storage facilities. In Ontario,4 for example, gas chlorination systems require a fire separation barrier between the chlorine storage area and the rest of the building. Gas chlorine storage also requires emergency air ventilation capable of exchanging the room’s air 30 times per hour. Building code requirements are unique to every region, so it is important to ensure pool areas are built to the applicable code.

Most building codes require the pool’s plumbing system to be clearly labelled. Pipes containing chlorine must be painted yellow, while pipes containing potable water must be painted green. A labelled plumbing system is important in the event that maintenance is being performed on the system, and the wrong pipe is accidently opened.

Best practice requires chlorine canisters, whether full or empty, to be securely anchored to prevent their accidental movement. When chlorine canisters are not attached to the chlorinator, a valve protection hood must be in place, and a wrench must be attached to each canister. These precautions are taken to avoid rupturing canisters and breaking valves. Providing the correct wrench, within arm’s-reach, gives operators a chance to quickly tighten loose, leaky fittings.

Granulated and liquid chlorine do not require the stringent engineering controls of gas chlorination systems, but precautions still need to be taken. Ventilation is important anytime pool chemicals are stored indoors. Pool houses can trap heat and cause chemicals to give off harmful vapours. Protecting workers can be as simple as letting a storage area air-out before entering, or providing respiratory equipment for workers.

Chlorine containers can be heavy; pool companies need to be considerate of the ergonomics in pool houses or chemical storage areas. Workers need proper ways to lift and pour chemicals to prevent spilling and splashing.

Employers can require two workers must lift heavy containers or provide special tools for lifting and administering chemicals. The appropriate measures an employer needs to take will depend on the specific storage area and its layout. In many instances, the pool company and its workers need to employ common sense when constructing areas where pool chemicals are going to be stored. 


Chlorine storage areas can incorporate a wide range of systems to protect its workers from harm, including leak-detection alarm systems, and emergency override switches.

Leak-detection systems can provide audible and visual warnings to workers before they enter a chlorine-contaminated area. These warning systems can also deter workers from opening contaminated areas and exposing the rest of the facility.

Override switches are another engineering control for gas chlorinators that protect workers. If a chlorine leak is occurring somewhere along the system, remote override switches can stop the leak away from the source and prevent workers from getting in harm’s way.


Proper and careful attention to the safe use of chlorine will minimize the chances of any injury to workers and/or the public, which will minimize the chance of a large monetary claim and perhaps eventually a large award for damages.

Chlorine gas is toxic, and companies can face fines for polluting; therefore, in some circumstances, it may be better to trap chlorine gas inside. This can allow a cleanup crew to enter and properly remove the trapped gas. Employees must be instructed beforehand on the appropriate emergency response,5 e.g., should workers keep the chlorine contained or vent it to the outside? Depending on the circumstances, either choice may be preferable.

As part of a company’s due diligence defence to quasi criminal or civil claims they should be able to offer detailed records of the work that was being performed, the chemicals that were being used, and by whom. Pool companies must also keep records of their chemical inventories, in case the scale of an accident is ever questioned. The onus is on the employer/operator to show they had taken all the necessary steps to protect their workers.

When the public is involved, the potential for tort lawsuits stemming from a chlorine or chemical accident is huge. Pool companies have a duty to protect swimmers and others in the pool area from potential chemical dangers. The public expects to enjoy a safe swimming experience, and pool companies are obligated to provide this. 


Chlorine is inherently harmful to human health. Protecting workers and members of the public requires a comprehensive, thorough, and holistic approach.

In the event of a legal claim by a member of the public, the pool operator/company will need to show it was proactively protecting the public by ensuring its employees properly and safely handled chlorine at all times.

Protecting the public and employees requires teamwork and a pool company needs to foster a culture of safety amongst all of their ranks, and it must begin at the top. 

Author’s note: The writing of this article was greatly assisted by law student, Ben Baena. 


1 See “$10M class action lawsuit filed after noxious chemical mix at St. Catherines pool,” CityNews (Aug. 3, 2012). For more information, visit (Accessed July 21, 2015).

2 See “Chlorine gas leak spurs $10M lawsuit,” Niagara Falls Review (Aug. 3, 2012). For more information, visit (Accessed July 21, 2015).

3 See the Occupational Health and Safety Act, RSO 1990, c O1. For more information, visit (Accessed July 21, 2015).

4 See the Building Code Act, O Reg 332/12, s 3.11. For more information, visit (Accessed July 21, 2015).

5 See “OSH Answers Fact Sheets–Chlorine” (Nov. 5, 2013), Canadian Centre for Occupational Health and Safety. For more information, visit (Accessed July 21, 2015).


See the Health Protection and Promotion Act, RRO 1990, Reg. 565—Public Pools. For more information, visit (Accessed July 21, 2015). 

Bio: Donald G. Kidd, BA, LLB, is a litigation partner at the law firm of SmithValeriote Law Firm LLP in Guelph, Ont. He has practiced employment and labour law, and has dealt regularly with other civil litigation matters for 38 years. He can be reached via e-mail at

The content of this article is intended to provide a general guide to the subject matter and is not legal advice. Specialist advice should be sought regarding your specific circumstance.