Hazard Watch - Understanding Chlorine in the workplace and its health risks

When we think of chlorine, the image in our heads is typically what goes into swimming pools as disinfectant. It’s also a very toxic substance and a powerful oxidizing agent and in the workplace, it can be really harmful.

Chlorine can be used in several industries, outside of decontaminating swimming pools. It is used in the manufacturing of chemicals, plastics, pharmaceuticals, pulp, paper, and pesticides. We’d like to talk about it as our latest Hazard Watch feature as exposure to pure chlorine can cause very serious health conditions. Employees have a right to expect certain safety processes to be in place, to limit exposure.

The hazard of chlorine in the workplace

It’s important to understand how chlorine can be a hazard. When it needs to be shipped or stored, chlorine gas has to be pressurised and cooled to change it into a liquid form first. When liquid chlorine is released, it can quickly turns into a gas that stays close to the ground and spreads rapidly. This can result in a serious hazard.

Chlorine in gas form is the most common and harmful route of exposure, via inhalation. However, exposure can also occur when chlorine gas is absorbed through the skin or eyes. Depending on the level of exposure, typical reactions can include a sore throat, difficulty breathing, irritation of the airways, chest tightness, as well as eye and skin irritation. More harmful exposure at higher levels can cause pulmonary oedema, and skin injuries similar to frostbite if exposed to liquid chlorine. If an individual is exposed to levels exceeding 400ppm, this can be fatal within 30 minutes.

Minimising or preventing exposure to chlorine

Chlorine exposure is usually accidental, either as a result of PPE being worn incorrectly or an accidental spill during the manufacturing process. Employees are strongly advised to make sure all personal protective equipment (PPE) is constantly worn in locations where chlorine is being used. These locations should be subject to strict monitoring measures.

The Health and Safety Executive (HSE) EH40 document states that the current workplace exposure limit for chlorine is 0.5ppm within a 15-minute period. Any employee that been exposed to chorine is strongly advised to leave the area immediately and ensure they thoroughly wash their skin, face, and eyes. High level exposure will be apparent due to the presenting symptoms, and urgent medical attention should be sought immediately.

Employers can take measures to prevent exposure too. To fully understand the current levels of exposure within your workplace, media such as silver membrane PTFE filters can be used by trained occupational hygienists as well as health and safety personnel. Samples should be subsequently analysed in line with the NIOSH 6011 method to accurately determine the levels of exposure.

Employees can be safer and better protected at work by consistently checking the levels of exposure are within the required limits in the workplace.

How can we help?

Within our state-of-the-art laboratory in Manchester, we can provide and analyse each of the recommended media types referenced above in line with the NIOSH 6011 method. We have deep expertise in providing certainty to workplaces that may have concerns for their employees’ exposure to chlorine.

Our highly skilled and knowledgeable team provide a personalised service, and we assist clients with the provision of suitable sampling media, analysis and if needed, recommendations on sampling guidelines.


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