Trends and research into respiratory protection

The field of respiratory protection has developed continually since the First World War when gas weapons created a requirement for mass-produced respirators for use by troops. The development of widespread chemical use in industry created the need for respiratory protection in the workplace and this requirement has continued. In this article, we explore the status and development of Standards associated with respiratory protection in the workplace, and research that was undertaken by a 3M employee through the University of Western Sydney to help understand the impact and level of compliance associated with the use of respirators.

In Australia today, guidance on the use and performance of respirators is given by two Australian standards, AS/NZS1715 'Selection, use and maintenance of respiratory protective devices' and AS/NZS1716 'Respiratory Protective Devices'.

The first standard is for respirator users and those responsible for respirators in the workplace and provides the information needed to run an effective respiratory program. The second standard sets the performance benchmarks that different types of respirators are needed to provide various levels of protection.

These standards were developed in the early nineties and published in 1994. There has been some recent updating and amending occurring with AS/NZS1716 released in its latest version in 2003. AS/NZS1715 is about to go out for public comment to update the 1994 version. Both updated versions are closely based on the 1994 Standards. However, it is apparent to the Standards Committee that there was a need for a large amount of new scientific information in areas such as testing regimes and basic physiology to set new benchmarks to effectively deal with current and developing issues regarding respiratory equipment application and required performance. It is recognised that Australia and New Zealand do not have the laboratory or manning resources and capabilities to obtain this type of information.

While the current AS/NZS 1715 and 1716 documents are still valid and provide a good framework for a respiratory protection program, there are developments occurring internationally that will change the scene in the years ahead.

The International Standards Organisation (ISO) is currently working on a global standard for respiratory protection. Initial discussions began in 2000 and the development process is now well under way. It is envisaged that a Standard will be produced in the next few years and that this standard will become the new version of the Australian Standards for respiratory protection, therefore becoming applicable in all Australian workplaces.

The new ISO standard is looking in depth at the issue of the physiological requirements of the respirator wearer - looking at issues like breathing requirements, face sizes and design and material parameters to try to more effectively align the design and operational features of respirators to their applications. To address the many issues associated with respiratory protection in a thorough manner, the broad topics were divided up among members of the ISO committees. For example, the issue of matching the respirator to the user is being given direct attention by a group looking at physiological requirements. The respiratory effects of the heavy physiological demands of persons, like firefighters or rescue operators, doing high activity work are being investigated. The basic research and data needed to answer the questions that have been raised in this context are currently being conducted in various facilities and organisations across the globe.

This approach is leading to extended research into basic physiological needs and is also looking to set performance restrictions and parameters for a respirator in certain modes of use - light work, heavy work, cold/hot work etc. Working in certain conditions will require certain features or performance characteristics for a respirator suitable for those conditions. In recent years, 3M has carried out a number of workplace protection factor studies to assist in determining the respiratory protection performance of certain types of respirators in real workplace conditions. This is an expensive and time-consuming undertaking that requires considerable resources. The process involves putting a number of workers doing their normal work (that requires regular use of a respirator) in specially modified respirators and sampling the level of airborne contaminants inside and outside the respirator. The ratio of these two measurements gives the protection factor afforded by the respirator. By doing enough tests on different workers and tasks, and then doing the appropriate statistical analysis, a workplace protection factor can be calculated. These factors give an indication of the actual and relative protection given by different types of respirators, information that can be used as input into the Standard development process. Testing in actual workplace conditions provides some indication of the effect of 'real world' factors like ease of fit, comfort, face-seal, sizing, heat (sweat), effect of training and others that can all have an effect on actual protection levels.

Other research has looked at assessing the level of compliance by industry with the current requirements of the Australian Standards together with collection of data from various end users across a range of industries, sizes and applications, and has found a number of trends.

To put this investigation into context, recall that the goals of a respiratory program are:

• Protect the wearer's health and well-being,
• Achieve legislative compliance,
• Reduce litigation potential with evidence of compliance,
• Provide value for money spent.

To achieve these aims, there are a number of areas that need direct attention to establish an effective respiratory program. Broadly speaking these areas are:

• Management responsibility,
• Workplace assessment,
• Selection (contaminant, person, task),
• Purchase and issue,
• Maintenance,
• Documentation (policy, program, records, audit).

Some of these areas were studied to determine the performance over time. The research has been carried out by way of surveys of individuals in these companies with knowledge of the respirator usage and protocols - in both small and large companies, and carried out over a 5-year period. These surveys compared the performance of each user company over this period across several categories.

The change in performance in these categories over the five years was measured and comparative results calculated. Some interesting outcomes were identified in this research.

More of those surveyed now have written programs and procedures for respirator use - an increase of 14 per cent. Aligned with this is a 22 per cent increase in those keeping records of training in respiratory protection and a 61 per cent increase in those recording respirator tasks ie, the details of who uses respirators, when and for what reason. Similarly, the collection of respirator maintenance records has increased by 33 per cent. It would appear that there has been a general improvement in awareness of the need for improved documentation in all areas of a respirator program, with regulatory and legal influences presumably to the fore in this regard. However, the other side of the coin is that nearly a quarter of those surveyed did not have any written programs or procedures or keep records of respirator use patterns.

There has been a 25 per cent increase in the occurrence of medical assessments for respirator users - this process giving some assurance that the potential user is physically fit and well enough to operate effectively with the extra physiological burden that some respirators impose on the wearer.

The need for initial fit testing and ongoing repeat fit testing (usually on an annual basis) is another area where some improvement has occurred. Fit testing is necessary to ensure that the potential wearer of any particular tight fitting facemask (full or half style) can get a good facial fit with that specific respirator model. It is clear to anyone who has done any fit testing that there is a range of facial types and features that can be very different and these will therefore require different sizes and styles of mask. Persons wearing masks that are not fit tested are gambling that they actually achieve a good seal on their face. The protection expected from a certain type of respirator will be compromised if the face fit is not satisfactory and overexposure to the airborne contaminant can readily occur. The study has shown that while there has been a greater than 40 per cent improvement in the occurrence of fit testing (initial and repeat), there is still a long way to go, with more than half of those surveyed having no fit test program in operation at all. In the context given above, this is a serious issue with potential adverse health outcomes for the many workers who are not regularly tested.

Other areas of some improvement include occurrence of training and repeat training on respiratory protection, and increase in provision of a centralised maintenance facility.

In general, the results show an overall improvement in meeting the requirements of an effective respiratory protection program. However, there are still significant gaps in the application or provision of the elements by many companies. Clearly there is still a way to go to achieve full compliance.

The advent of the new ISO standards will change the landscape of respiratory protection when it is released. However, the goal is a Standard that will provide a framework giving guidance and assistance in implementing a respiratory protection program and allowing the use of various respiratory equipment well suited to a range of tasks and applications.

* Terry Gorman, M.Safety Science (UNSW), Certified Occupational Hygienist, Member Australian Standards Committee SF-010 (Respiratory Protection), Member ISO TC94 SC15 Respiratory Protection Standard, authored this article. Terry is currently employed by 3M as occupational hygienist, and is well known by many occupational hygienists around Australia.