Control of Substances Hazardous to Health (COSHH) is the law that require employers to control substances that are hazardous to health and includes nanomaterials. This blog post covers some notable regulations imposed by COSHH on using an ozone generator.

Workplace Exposure Limit (WEL)

To maintain ozone exposure limits, appropriate control practices should be applied when exposure to ozone cannot be prevented. The current limit for ozone in the workplace is 0.2 ppm in air over a 15-minute reference period.

Employers must not carry out any work that might expose employees to harmful substances in accordance with COSHH regulation 6. If they have not assessed how those tasks may impact the health of those employees, and what steps they must take to meet COSHH requirements, they cannot carry out those tasks. If there is a chance of exposure to ozone, you should carry out a ‘suitable and sufficient’ risk assessment.

The HSE guide to COSHH assessment describes how to make an assessment in general terms. Furthermore, the COSHH ACOP contains guidance on how to make an assessment. An action plan for the assessment would involve:

■ Is exposure likely?

■ Can the exposure be prevented?

■ Where is ozone likely to be generated?

■ Who is likely to be exposed?

■ The exposure level needs to be estimated when exposure is not preventable (your personal exposure monitoring may be required for this). If the level of exposure estimated is unlikely to exceed the recommended exposure limit, no further action is required.

■ Make sure that any exposures exceeding the workplace exposure limit (WEL) are controlled and appropriate measures are taken.

Also, it is important that assessment must be reviewed regularly.

Low-risk work activities

Work activities that expose individuals to small amounts of ozone can cause no significant health problems. Office-type environments are the most common place to encounter low-risk exposures to ozone.  

Employers should be aware that in inadequately ventilated rooms, ozone levels may rise above the WEL in some cases. However, any symptoms will generally be related to respiratory irritation.

To ensure the WEL is not exceeded, manufacturers and suppliers should provide recommendations on how such equipment should be used and installed, and you probably won’t need to do anything more than follow the recommendations. Whenever possible, it is advisable to place the equipment in a dedicated room. If this is not feasible, it may be necessary to place it in an area which has good ventilation. A more comprehensive assessment of the potential risks is needed if the facility is not sited according to manufacturer’s recommendations.

The health benefits of ozone include oxidizing organic matter and decreasing the growth of bacteria. Ozone generators used in offices and as odor suppressors take advantage of this beneficial effect.  

Whenever possible, employers need to make sure that their workers are aware of the precautions to be taken to reduce exposure to ozone and the various controls being employed. Employees should be instructed to contact their supervisor or employer if they notice any problems, such as closed ventilation windows in copier rooms.

Higher-risk work activities

COSHH requires precautions be taken when employees are likely to be exposed to hazardous substances. In the case of ozone, work activities such as those outlined above pose a significant risk of exposure. In the remainder of this guidance, employers are guided on the controls they should take to control such exposures. Higher levels of ozone can cause serious health effects and increase the risk for people.

Learn more about how you can prevent ozone dangers here.