Employers must ensure workplaces are well ventilated to minimise COVID-19 spread

Businesses are being reminded that they have a legal duty to ensure that their premises have an adequate supply of fresh air in enclosed areas as part of a broad strategy to minimise the risk of the coronavirus from spreading via workplaces. 

With most COVID-19 restrictions lifted, Great Britain’s Health and Safety Executive (HSE) has updated its guidance on ventilation and air conditioning as part of a package of preventative measures to help safely manage the increasing number of people returning to the workplace and to reduce infection risk. 

The guidance explains how natural and mechanical ventilation can reduce coronavirus in the air while also reiterating the importance of workers keeping clean and washing their hands frequently. The updated advice also reemphasises the importance of risk assessments to identify other control measures such as social distancing and the wearing of masks. 

‘You can improve natural ventilation in the workplace by doing simple things like opening windows and doors and can improve mechanical ventilation by understanding how your systems work and by making sure they’re working properly,’ says Dr Alexander Tsavalos, HSE’s head of Covid sector policy. 

‘The use of CO₂ monitors in the workplace can also help. Although CO₂ levels are not a direct measure of possible exposure to COVID-19, checking levels using a monitor can help you identify poorly ventilated areas.’

The HSE has announced that it will continue to carry out spot checks and inspections to support businesses and ensure they understand its ‘working safely’ guidance.

IOSH concurs that employers should prioritise preventative measures and adds that good ventilation will play a critical role in controlling the risk of coronavirus as businesses increasingly encourage home-based staff to return after a prolonged period working remotely. 

By identifying the risks of COVID-19 transmission, employers can identify proportionate controls to prevent and manage those risks in the workplace and protect staff and others

The institution argues that a ‘risk-based approach’ is a critical first step. Risk assessments must be in place to identify COVID-19 as a hazard and the associated risks. They will also identify who is at most risk and the measures to take. 

‘By identifying the risks of COVID-19 transmission, employers can identify proportionate controls to prevent and manage those risks in the workplace and protect staff and others,’ says Ruth Wilkinson, head of health and safety at IOSH. 

Last September, IOSH magazine published an article that explored how COVID-19 risk assessments can be informed, taking into consideration the fact that unlike risks such as legionella and asbestos, the OSH community is still learning about the virus’ transmission and the most effective controls . 

The article includes a number of case studies published by the US Centres for Disease Control and Prevention that demonstrate the importance of preventative measures. 

As one of the case studies involving a call centre outbreak in Seoul, South Korea emphasises, ‘being in an enclosed space, in a crowded office environment and sharing the same air for a prolonged period is very high risk for exposure and infection’.  

IOSH advises employers to revisit pre-COVID-19 workplace risk assessments and ensure that any additional controls necessary to make the workplace secure from the virus are identified and do not exacerbate existing risks.  

Review guidelines and sources of information to identify if any new information, guidelines or control requirements have been amended and changed, which will impact your control strategies

‘As with any risk assessment, it is important that employers have arrangements in place to monitor and review them,’ says Wilkinson. 

‘As part of this process, employers should review incidents, seek feedback from staff and review control measures to see if they remain effective. Also, review guidelines and sources of information to identify if any new information, guidelines or control requirements have been amended and changed, which will impact your control strategies. Risk assessments must be kept valid and up-to-date and workers informed’. 

Employee engagement is critical to managing risks successfully. To maximise buy-in and thereby improve the effectiveness of risk assessments, the HSE has produced a separate guide to help employers consult with staff on how to work safely.

IOSH has published its own return to work guidance, which notes that while masks and social distancing have been the more visible signs of controls, good ventilation is a largely unseen, albeit highly effective, measure to control the risk of infection.

‘As employers are reviewing their risk assessments and guidance on controls are changing, it is important that employers review risk assessments and implement controls as necessary to prevent and manage the risks in their workplaces,’ says Wilkinson. ‘Ventilation, whether mechanical, natural or both, is a key measure in diluting contaminated aerosols’.  

As the guidance notes, small aerosols can stay airborne for hours, enabling pathogens to travel longer distances and potentially infect secondary hosts, particularly where spaces are poorly ventilated. 

Earlier this year, IOSH magazine reported a poll of 2,000 representative adults, which indicated that 68% of respondents believed that businesses and employers should do more to provide clean air in the premises. 

It is important that areas of poor ventilation are identified, so that action can be taken around the use of that space, and the identification of available sources of ventilation considered

The survey by facilities management company Rentokil Initial suggested that the risks of airborne coronavirus transmission could prevent a third of workers returning to the workplace.

To better safeguard employees, IOSH argues that employers need to avoid using air circulation systems that only circulate the air in the space as this will spread the virus throughout the building, potentially infecting more staff.   

The institution also warns that increasing air flow by opening doors through natural ventilation cannot be at the expense of fire separation measures. It adds that fire separation doors must remain shut or on release mechanisms linked to the fire alarm system because ‘fire risk is still by far the greater risk’. 

‘It is important that areas of poor ventilation are identified, so that action can be taken around the use of that space, and the identification of available sources of ventilation considered,’ says Wilkinson. 

‘As always, employers must identify if new hazards or risks are being introduced as a result of any changes being made, for example, to current fire, or security arrangements. 

‘To protect employees and others from harm, risk assessments must identify hazards and the risk, and take action to eliminate the hazard or control the risk. COVID-19 is one such hazard, but employers must still take action to protect staff and others from those other sources of harm.’

IOSH’s guidance also highlights the potential risks in the events sector, which was forced to keep venues closed during the height of the pandemic. As event bookings begin to pick up, IOSH has reiterated the importance of building system inspections to ensure that dormant ventilation systems haven’t been compromised and can be operated safely and effectively.

The Institution advises event companies and venue owners to ensure that ventilation systems are effective, are well maintained and therefore ‘safe and fit for purpose’.

Source: IOSH Magazine