Managing COVID-19 risks: Healthcare and social assistance industry – Respiratory Protective Equipment (RPE)

Background

This should be read together with 'Prevention and management of exposure to COVID-19 in the healthcare and social assistance industry.'

Researchers are still learning about COVID-19, its long-term effects and emerging variants.

COVID-19 is a respiratory disease caused by a coronavirus (SARS-CoV-2) that can result in mild to very severe illness and death.

The main way COVID-19 spreads is when a person with COVID-19 exhales droplets and/or aerosol particles containing the virus. This can happen when they breathe out, cough, sneeze, speak, shout or sing.

Exhaled droplets range in size. Large droplets settle out of the air faster than they evaporate. Small droplets remain suspended in the air for longer periods. Very fine droplets may contain the virus, and can stay suspended in the air for anywhere from minutes to hours. Small droplets and particles are often referred to as 'aerosols'.

Transmission of COVID-19 can occur in a number of ways, and possibly in combination.

1. Airborne transmission

This occurs when a person inhales aerosols that may contain viral particles that are infectious.

While the risk of transmission is highest when close to an infectious person, air currents can disperse small droplets and particles over long distances. These may be inhaled by people who have not had face-to-face contact or been in the same space with the infectious person. Airborne transmission is more likely to occur in indoor or enclosed settings that are poorly ventilated, crowded, or both. In these kinds of settings, the virus may remain suspended in the air for longer and increase the risk of spread as people tend to spend longer periods in indoor settings.

2. Droplet transmission

Transmission occurs where exhaled droplets from a person with COVID-19 come into contact with another person’s mucosal surfaces (nose, mouth or eyes). The risk of transmission is highest when close to the source, where the concentration of these droplets is greatest.

3. Contaminated surfaces transmission

People may also become infected by touching surfaces that have been contaminated by the virus, and then touching their eyes, nose or mouth without cleaning their hands.

Identifying and controlling risks associated with COVID-19 in the healthcare and social assistance industry

Employers have a duty to provide and maintain, so far as is reasonably practicable, a working environment that is safe and without risks to the health of employees.

Employees have a duty to take reasonable care of the health and safety of themselves and others in the workplace, and to cooperate with any action their employer takes to comply with a requirement imposed by the OHS Act or OHS Regulations.

Where a risk to health associated with potential exposure to COVID-19 is identified at a workplace, employers must eliminate the risk so far as is reasonably practicable. Where it is not possible to eliminate the risk, it must be controlled so far as is reasonably practicable.

Control measures may include the use of personal protective equipment (PPE) including RPE. However, PPE is the lowest order of control and must always be used in combination with other control measures to reduce the risk of exposure to COVID-19. The WorkSafe website has information to help employers understand and use the hierarchy of control.

Use of respiratory protective equipment

Where RPE is required to protect employees from airborne hazards, employers should have a respiratory protection program in place. A program includes selection of a P2/N95 respirator that is appropriate for tasks, correct size and fit testing, and training on the use and limitations of respirators. More information on respiratory protection programs can be found in the Australian/New Zealand Standard on 'Selection, use and maintenance of respiratory protective equipment' (AS/NZS 1715:2009).

Fit testing

Fit testing is the method for checking that a tightfitting P2/N95 respirator matches the wearer's facial features and seals adequately to the wearer's face. It will help to identify unsuitable styles of P2/N95 respirators that do not provide adequate protection and should not be used by the individual wearer, and conversely suitable styles of respirators that should be used by the individual wearer.   It involves the use of either an instrument or a test hood to detect any leakage of the N95/P2 respirator. If a wearer is unable to achieve a pass, they should select another style of N95/P2 respirator until a pass can be achieved.

It should be conducted prior to the need to use a P2/N95 respirator so that a suitable respirator can be identified for the wearer. Fit testing is an important part of a respiratory protection program per AS/NZS 1715:2009, and should be conducted so far as reasonably practicable.

More information on respiratory protection programs can be found in the Australian/New Zealand Standard on 'Selection, use and maintenance of respiratory protective equipment' (AS/NZS 1715:2009).

Even when it is not reasonably practicable to undertake fit testing prior to use, people must do the following every time a N95/P2 respirator is worn:

• follow the instructions on how to put on the respirator (i.e. donning) described below
• perform the fit check as described below
• make sure that they are clean-shaven where the N95/P2 respirator touches the face
• make sure no clothing or jewellery gets between the N95/P2 respirator and the face

Studies have shown that people still receive some reduction in exposure if they follow this procedure. However, the level of protection provided by the P2/N95 respirators may be lower without fit testing.

Selection of RPE

Selection of the type of RPE required to be worn by employees depends on factors including:

• the type of activity
• the duration of the activity
• the likely form of transmission for the activity being undertaken (contact, droplet, or airborne)
• the level of risk of exposure to COVID-19
• the ability to achieve an adequate fit (and therefore level of protection) with a P2/N95 respirator
• the availability or supply of RPE in the workplace

In addition to RPE, other PPE may also be required, including safety glasses / goggles or face shields, long-sleeved gowns and gloves.

Types of RPE

The most common types of RPE used in the healthcare and social assistance industry include:

Single use disposable respirators

• Disposable P2 and N95 non-surgical (standard) respirators – tight fitting masks designed to protect the wearer from fine and coarse aerosols and droplets. These respirators are suitable for use in settings where there is unlikely to be fluid spray beyond a cough or sneeze.
• Disposable P2/N95 surgical respirators - tight fitting masks designed to protect the wearer from fine and coarse aerosols, droplets, and fluid splashes or high velocity streams.

The terms 'P2 respirator' and 'N95 respirator' are often used interchangeably in healthcare settings. They are regarded as providing an equivalent level of protection for biologically active airborne particles and aerosols. The difference between these respirators is the different regulatory standards they are required to meet around the world. In Australia, the requirements for P2 respirators are stated in the Australian / New Zealand Standard on Respiratory protective devices (AS/NZS 1716:2012). The United States National Institute of Occupational Safety and Health (NIOSH) specifies N95 respirator requirements.

Reusable face fitting respirators

Half facepiece or full facepiece tight-fitting respirators consist of facepieces which are made of synthetic or natural rubber material. These respirators can be repeatedly used after appropriate cleaning, disinfection and storage according to the manufacturer’s instructions. Some types of non-disposable half or full facepiece respirators offer higher assigned protection factors (APF) than disposable P2/N95 respirators. Reusable respirators also have adjustable straps that may accommodate a better fit.

Powered Air-Purifying Respirators (PAPR)

A PAPR is a battery-powered device that provides filtered air under positive pressure into either a loose-fitting hood or helmet or a tight-fitting face piece. Because the filtered air is delivered under positive pressure, the device can compensate for an imperfect seal. For this reason, a PAPR is regarded as potentially providing a higher level of protection than other RPE. PAPRs can offer APF ranging up to 100+ compared to an APF of 10 provided by N95s. PAPRs with loose-fitting hoods can provide additional advantages in that they do not need to be fit tested and they can be used by health care workers who cannot achieve an acceptable seal due to facial hair or other reasons.

The most common concern regarding the use of PAPRs has been their effect on the sterile field, such as during surgery, as PAPRs do not filter the discharged air. Some health care facilities have tried using surgical masks under the loose-fitting head coverings or placing the ends of the PAPR hood under the surgical gown, but neither is a tested or certified configuration.

Note: Reusable respirators with exhalation valves

Respirators with exhalation valves protect the wearer from airborne COVID-19 particles but may not prevent the virus spreading from the wearer to others because some models do not have filters on the exhalation valve. The exhalation valve is designed to open during exhalation to allow exhaled air to exit the respirator and then it closes tightly during inhalation.

Reusable respirators with no filter on the exhalation valve are not generally recommended to be used due to the risk of unfiltered air or SARS-CoV-2 (from an infected wearer) being expelled through the exhalation valve contaminating the surrounding environment and potentially exposing other individuals. However, during situations where protecting the wearer from infected individuals is the priority, such as in a setting with confirmed COVID positive individuals, reusable respirators with no filter can provide a suitable option. An assessment would need to be made on where such respirators may be used as there will be some situations where their use is not recommended such as in sterile areas and operating theatres.

In addition, there is evidence that shows that even a reusable respirator with no filter on an exhalation valve can offer more protection to others from the wearer than the protection afforded by a surgical mask.

Wearing and fitting of P2/N95 respirators

A summary of how P2/N95 respirators should be fitted and worn is provided below.

• selection of appropriate size and shape to fit facial characteristics
• must be clean-shaven or free from facial hair under the sealing surface area of the respirator
• If an employee is unable to shave or has a non-standard facial structure or size, then PAPRs that do not rely on a facial seal may be considered as an alternative. Some PAPR hoods do not need to seal to the wearer's skin to work correctly and are designed instead to fit loosely under the wearer's chin or at their neck.

How to wear (donning)

• rest the nose bridge on top of the nose and place the bottom panel or bottom of cup securely under chin
• the straps are secured at the back of the middle of the head and neck
• position and mould nose piece (where available) around nose using fingertips of both hands

Refer to DH guidance on putting on (donning) PPE for more details.

Fit check

• place one or both hands completely over the middle panel or cup
• inhale and exhale sharply
• check for air leaks around the nose
• adjust respirator until no leaks can be felt

Note: If tight fitting seal cannot be achieved with one brand of respirator, then it might be achieved with a different shaped N95/P2 respirator. If a seal cannot be achieved, then the task should not be performed.

Removing respiratory protection (doffing)

Prior to removing respiratory protection, it is important to move to a clean area (doffing station) to avoid exposure to any hazardous airborne contaminants.

It is important to be aware that any potentially infectious particles will remain on the outside surfaces of the P2/N95 respirator or the filter fibres. A P2/N95 respirator is therefore a potential source of contact contamination after use.

When removing a P2/N95 respirator, take care not to touch the outside, discard it with other potentially contaminated for cleaning or dispose as waste, and perform hand hygiene (wash your hands or use hand sanitiser) immediately after handling.

Refer to DH guidance on removing (doffing) PPE for more details.

Time limitations

There is no specific time limit for the continuous use of a disposable surgical mask or N95/P2 respirator over the course of a shift.

A disposable N95/P2 respirator should be disposed of immediately:

• after an aerosol-generating procedure (AGP) is performed
• if the exterior is soiled or contaminated
• if it is damaged
• if it has been coughed or sneezed into
• if it no longer fits tightly to the face
• if it becomes damp

There is no specific time limitation for the disposal of filters in a non-disposable respirator however the manufacturer's/supplier's recommendations should be consulted and followed.

Re-use of disposable P2/N95 respirators

Disposable P2/N95 respirators are single use and not designed to be reused. Currently there is no evidence that disposable masks and P2/N95 respirators can be safely sterilised and reused.

If an employee feels unwell

If an employee develops symptoms of COVID-19 they should isolate themselves immediately, call the Victorian Coronavirus Hotline on 1800 675 398 or their doctor and follow the self-isolation guidance available on the DH website.

The symptoms of COVID-19 to watch out for are: fever, chills or sweats, cough, sore throat, shortness of breath, runny nose and loss or change in sense of smell or taste. Some people may also experience headache, muscle soreness, stuffy nose, nausea, vomiting and diarrhoea.

An employer's duty to eliminate or reduce risks associated with exposure to COVID-19 so far as is reasonably practicable includes ensuring that:

• employees know what to do or who to notify if they feel unwell or suspect they’ve been infected, according to the information provided by DH
• any unwell employee does not attend the workplace, including employees who have been tested for COVID-19 or who are confirmed COVID-19 cases

In the event of a suspected or confirmed COVID-19 case at the workplace, Pandemic Orders made by the Victorian Minister for Health may also require employers to take specific response actions.

References

• AS/NZS 1715:2009 'Selection, use and maintenance of respiratory protective equipment.
• Victorian Department of Health: Victorian Respiratory Protection Program guidelines.
• Brian Rembialkowski, Margaret Sietsema & Lisa Brosseau (2017) Impact of time and assisted donning on respirator fit, Journal of Occupational and Environmental Hygiene, 14:9, 669-673.