Are ozone laundry systems safe?
Ozone provides a safe method of disinfection for on-premise commercial laundry rooms, when used correctly and with best practice in line with the Control of Substances Hazardous to Health (COSHH) Regulations 2002.
Ozone has been safely produced in industrial environments for many years, for example to improve air quality in offices, as an odour suppressor in hotel rooms, in commercial kitchens, as a disinfectant for drinking water, water treatment for swimming pools and also in laundry. O3 is actually present in the air we breathe at a typical concentration of 0.002 to 0.1 mg/m3 (0.001 to 0.05ppm) and is detectable at very low concentrations. It can be used with safety in industry and under normal circumstances the risk to health is slight.
Ozone and general laundry safety
As is the case with any chemical, ozone can carry a degree of risk if proper measures are not put in place during its use. However, following the eight principles of good practice set out in Schedule 2A of the COSSH Regulations will ensure the adequate level of safety for ozone laundry system operators.
- Design and operate processes and activities to minimise emission, release and spread of substances hazardous to health.
- Take into account all relevant routes of exposure – inhalation, skin absorption and ingestion – when developing control measures.
- Control exposure by measures that are proportionate to the health risk.
- Choose the most effective and reliable control options that minimise the escape and spread of substances hazardous to health.
- Where adequate control of exposure cannot be achieved by other means, provide, in combination with other control measures, suitable personal protective equipment.
- Check and review regularly all elements of control measures for their continuing effectiveness.
- Inform and train all employees on the hazards and risks from the substances with which they work and the use of control measures developed to minimise the risks.
- Ensure that the introduction of control measures does not increase the overall risk to health and safety.
Guidelines for safe ozone exposure in commercial settings
The Health & Safety Executive (HSE) Workplace Exposure Limit (WEL) for ozone is 0.2 parts per million (ppm) over a 15 minute period. With the correct procedures in place, exposure to ozone for laundry operators should usually be well below 0.1ppm.
In independent tests carried out on a range of laundry configurations (basements etc.,) the ozone levels were found to be in the region of 0.03 and 0.05 ppm for JLA’s OTEX ozone laundry system.
For further peace of mind, JLA’s OTEX ozone laundry system incorporates ozone sensors, which will monitor the exposure levels of ozone within the laundry room. At 0.10ppm the operator will be alerted to the potential level of ozone. This may occur if a small load is being processed or a single item such as a duvet or pillow. At 0.18ppm a warning alert is given and the system automatically shuts down the generation of ozone (but not the washing machines). Ozone generation will only restart once ozone levels have fallen below 0.15ppm controlled by the fully automatic system.
Ozone and the environment
Regarding the environmental impact of discharging ozone-impregnated waste water into public sewers WRc-NSF conducted an assessment of the potential risk of release of ozone into mains sewers from laundry process waste water. Unlike other laundry chemicals which can scavenge oxygen when discharged from the wash process and affect aquatic eco systems, ozone rapidly degrades back to oxygen. The systems are safe in environmentally sensitive areas such as those serviced with reed beds and septic tanks.
Ozone and fabric care
As ozone is soluble in cold water the need for temperature is eliminated for disinfection purposes with obvious advantages to both the linen and the utilities. Temperature is only required to enhance the wash process and provide the right conditions for stain removal. A gentler wash process prolongs linens. Fabrics which wouldn’t otherwise be suitable for decontamination can be effectively disinfected by ozone reducing the costs for replacement and the need to destroy after use.
Ozone can be used safely on linen in contact with oils – such as spa’s kitchens etc.. with the right chemistry the oils can be safely removed using lower temperature than traditional processes with the added advantage that the laundry is thoroughly disinfected, even heat sensitive micro-organisms such as E Coli which can survive thermal temperatures of +80°C in wash processes. This is important for those establishments using communal linen facilities as well as those where they serve the most vulnerable – for infection control.
5 tips to make sure your ozone laundry system is safe to use
- Any prospective ozone laundry system should be designed to minimise O3 exposure. A washing machine is in essence a sealed container during the laundry process, and the emission of ozone during a cycle should be controlled and minimised to prevent release into the wider laundry environment.
- The exposure route will be via inhalation – it’s important therefore to ensure your laundry room is adequately ventilated and provides the relative amount of fresh air into the room to assist in the dispersion of any residual ozone, thereby reducing the exposure levels.
- Additional control can be provided by ensuring the system you choose has an ozone room sensor, which controls the generation of ozone so that any ambient levels are managed well below the HSE’s Workplace Exposure Limit.
- Before installing an ozone system, confirm with your supplier that it will come with full service engineering support – ensuring that all safety controls are working correctly and regularly checked and recalibrated as required.
- Restrict ozone laundry systems to professional use only. Your laundry partner should provide appropriate training, and only authorised staff must be allowed to operate the system. The provision of high quality manuals and information relating to the system and its operation is also vital.
To discuss the safety of ozone laundry systems in general or ask about any specific concerns you have, please contact us today to arrange a call or meeting with our in-house chemist.
References: 1 – HSE Guidance Note EH38 (3rd Edition 2014) 2 – HSE Summary Criteria For Occupational Exposure Limits EH64 (2002)