The Fundamentals of an Effective Mask Fit Test Program
The Importance of Mask Fit Test Programs
Mask fit testing programs are an essential element in protecting workers from exposure to air contaminants. Any level of exposure to hazardous particles, vapour or gas can lead to short and long-term health impacts such as occupational lung diseases. The last layer of protection for workers against these hazards is a properly fitted mask. Personal protective equipment (PPE) which does not fit correctly places workers at risk and is a waste of resources for employers. Inadequate respiratory protective device programs, including improperly fitted or ineffective masks, has in recent times been linked to a growing number of terminal silicosis cases. Fit testing respirators ensures workers are protected from contaminants which may be harmful, even if the level of harm is currently unknown. Effective fit testing programs may also reduce any potential liability for employers by preventing exposure to harmful airborne substances before long-term negative health outcomes occur. .
Fundamentals of an Effective Mask Fit Test Program
There are a number of components that are essential for a mask fit test program to be effective in protecting employees and mitigating liability risk for employers.
Ensuring Compliance to Applicable Australian Standards and Regulations
The best way to protect workers exposed to hazardous airborne substances is to ensure compliance with all relevant standards and regulations. While mask fit testing is not mandatory in all industries, it is in some, in particular, mining, construction when exposed to asbestos or silica, medical and more. AS/NZS 1715:2009 is the Australian and New Zealand Standard that sets out requirements and guidelines for the selection, use, and maintenance of respiratory protective equipment (RPE) in the workplace. The other standard to be aware of relating to fit testing in the workplace is AS/NZS 1716:2012. This specifies the requirements, performance and testing criteria for the manufacture of respiratory protective devices. The standard applies to all types of respirators, including half-face masks, full-face masks, and powered air purifying respirators (PAPRs). It also covers respirators that are used in occupational, industrial, and medical settings.
Selection of the Appropriate Respirator for the Job
Respirators must be carefully chosen depending on the nature of the work being completed and the airborne hazards they may be exposed to. In some industries, disposable masks may be the most appropriate option such as in hospitals where medical practitioners must replace masks regularly due to exposure to pathogens. In contrast, workers who are exposed to silica dust should wear a full-face respirator with a P3 class filter as recommended by Safe Work Australia.
Factors to be considered when selecting an appropriate respirator include but are not limited to:
The airborne contaminants which the worker is being exposed to.
The task the worker performs.
Physiological characteristics of the worker such as facial hair or weight loss.
Limitations of the respirator supplied including how it may impact the worker’s vision, communication and mobility.
Medical conditions which may cause certain types of respirators to place physical and psychological stress on the user.
Training and Education on Proper Use and Maintenance of Respirators
A mask fit test program should provide comprehensive training on how to wear, inspect, put on, remove, and maintain the respirators correctly. Training should always be provided before use of the respiratory protective equipment has begun and include information about the capabilities and limitations of the respiratory protective equipment selected. Routinely conducting and reviewing training annually and whenever there are changes in the workplace environment, procedures or type of respirators will ensure respirators are used effectively and in accordance with the most up to date and relevant standards.
Selecting the Appropriate Fit Test Method
There are two distinct types of fit tests, qualitative (QLFT) and quantitative (QNFT). Qualitative testing involves a distinct smelling or tasting substance being introduced to the respiratory system. The mask will be considered well-fitting if the subject of the test does not detect the smell or taste. The alternative is a quantitative fit test. QLFT is inherently less accurate than QNFT because an individual’s sense of smell or taste is subjective. Quantitative tests can be conducted using ambient aerosol technology (CNC), such as the TSI PortaCount, or controlled negative pressure (CNP) technology which is utilised by the OHD QuantiFit2. Both methodologies provide a precise ‘fit factor’ value which represents the volume of the challenge agent which leaks into the mask. While both CNP and CNC have been proven to be highly proficient in identifying leaks in respirator masks, CNP exhibits greater sensitivity with its ability to detect even the minutest leaks that may have gone unnoticed by CNC fit testers. The OHD QuantiFit2's sole restriction lies in its inability to assess disposable masks due to its utilisation of CNP technology. In such instances, the TSI PortaCount would be a suitable alternative for evaluating masks like P2 or N95 respirators.
Ensuring a Qualified Personnel Conducts the Fit Test
Whilst it is not legally required for respirator fit testers to be accredited in Australia, having an accredited tester will streamline the testing procedure and reduce the risk of untrained human error. Additionally, ISO standards (ISO/TS 16975-1:2016) state that fit testers should have adequate theoretical knowledge and practical skills in conducting a respiratory protective device fitting program. Accreditation may be obtained through the RESP-FIT Training and Accreditation Program, which trains candidates in QLFT and both types of QNFT, according to Australian and International fit testing standards.
Adequate Frequency of Fit Testing
Fit testing for respirators should not be conducted only once. It should be at least conducted annually, as well as when the worker is subject to change in any physiological characteristics such as weight gain, weight loss or facial hair growth occurs. If the type of respirator being worn changes, it is essential to conduct fit testing for each new piece of respiratory protective equipment to ensure effective protection from contaminants. Even if none of these changes have occurred, frequently conducting fit testing also ensures that workers maintain the ability to effectively don their respiratory protective equipment. Masks can also be donned multiple times in a single fit test in the redon protocol to ensure a proper and realistic fit is achieved.
Keeping Detailed Fit Test Written Records
Written, up to date records are necessary to demonstrate compliance with relevant standards. Keeping written records is a requirement under AS/NZS 1715:2009. Employers benefit from keeping written records as they may be used to illustrate that training, maintenance and evaluation processes are all being complied with. Advancements in fit testing instrumentation have enabled most respirator fit testing devices on the market, such as the OHD Quantifit2, to store fit test results electronically and print copies as needed. This eliminates the need to manually create and maintain paper records, saving employers a significant amount of time and administrative resources. In addition, electronic records can be easily accessed and shared, making it easier to track fit test compliance and ensure that workers are properly protected.
Evaluation of Respirator Fit Test Programs
Evaluation of fit test programs is a fundamental component of ensuring that workers are properly protected from harmful airborne contaminants. This process involves reviewing the fit test procedures, equipment, and personnel to identify any potential weaknesses. It also includes assessing the effectiveness of the fit test program by reviewing records and conducting follow-up testing. By evaluating the program on a regular basis, employers can identify and address any problems before resulting in exposure to hazardous substances. Programs must be adaptable, and employers must be willing to change programs where necessary based on evaluation to improve systematic performance and health outcomes.
Air-Met Scientific is the exclusive distributor and service centre for the OHD Fit Testing product range in Australia.
