Waiting for OSHA's APFs

Article From: Products Finishing, , from Occupational Health & Safety magazine

Posted on: 2/1/2002

With OSHA taking longer than expected to add the Assigned Protection Factors table to its respiratory standard, manufacturers and IHs still debate how to accomplish it...

CLICK IMAGE TO ENLARGE (+)

Painters use them. Welders use them. Employees working in laboratories that contain dangerous chemicals have them at their disposal. Firefighters often depend on them to stay alive in crisis situations. Despite the fact that respirators protect many workers from the harsh elements associated with hazardous jobs, many employees are unaware of how a specific respirator is chosen for a given task.

In most cases, workers rely on the ability of their company's industrial hygienist or other safety professional to assess work conditions and then choose the proper equipment. They know this is done to protect the company's most important investment--the highly trained employees themselves. But are the safety professionals able to make those decisions concerning respirators equipped with as much product information as possible? The answer lies somewhere behind a table of numbers called Assigned Protection Factors.

An APF is a number given to classes of respirators that "reflects the level of protection that a properly functioning respirator would be expected to provide to a population of properly-fitted and trained users," according to an OSHA statement. John Vincent, who is product manager, respiratory, for North Safety Products, says APFs can be found "by calculating a hazard ratio--the ratio of the contaminant concentration expected in the workplace to the occupational exposure limit for that contaminant. The resulting hazard ratio is then compared with the chosen respirator to make sure that the APF for that respirator is greater than the hazard ratio."

APFs are considered vital to determining what type of respirator is necessary for different types of hazardous jobs. In spite of this, OSHA failed to include a list of APFs in its 1998 respirator rule, 29 CFR 1910.134, but it indicated an APF list would be the subject of a separate rulemaking later that year. When the inclusion of APFs failed to happen, OSHA began setting new timelines for when it would address the issue. But many are beginning to question why three years have passed without any type of movement on a topic so critical to the protection of workers. The answer, according to some, has nothing to do with respirators.

"Once the ergonomics rule was announced as a priority, virtually all other projects and issues came to a complete halt," says Janice Bradley, technical director of the International Safety Equipment Association.

Ms. Bradley is just one of many in the industry who point to the ergonomics debate as the main stumbling block on making progress on the APF issue. Manufacturers also point to the now-defunct ergonomics standard as the main reason why there has been such a delay. "OSHA's priorities changed," says William Newcomb, director of regulatory affairs and standards development at North Safety Products. "Specifically, ergonomics took center stage."

Starting Again?

While the ergonomics issue still requires much of OSHA's attention, there has been recent speculation that the agency might again be turning its attention to APFs under its new administrator, John Henshaw. Those rumors were bolstered when, in a recent letter to Mr. Henshaw, ISEA President Daniel Shipp wrote "ISEA urges OSHA to complete the respirator standard by adding respirator APFs to the standard using the appropriate public comment process. Proper consideration should be given to national consensus standards, specifically ANSI Z88.2-1992, which includes the most scientifically validated APF table."

But while OSHA may now be feeling more pressure from manufacturers and industry organizations to include APFs in the standard, none of those groups can come to a consensus as to how APFs should be established. What's worse, there is no standardized method for determining protection factors.

At a recent roundtable, "Assigned Protection Factors: How Should They Be Established?" industry leaders outlined the many formulas that exist to test a respirator's APF and the countless ways the data from those tests can be interpreted.

Howard Cohen of the University of New Haven spoke at the roundtable. He described and advocated the use of Simulated Workplace Protection Factor (SWPF) studies to gather information on particular respirators. Larry Janssen, a Certified Industrial Hygienist at the 3M Occupational Health & Environmental Safety Division Laboratory, says SWPF studies are done in a lab and measure atmosphere both inside and outside a respirator while the person wearing the device performs "a series of exercises intended to simulate real work."

Cohen cited several advantages to using SWPF studies, including the ability to monitor and manipulate the work environment and to test specific respirators at different times and under various conditions. Not everyone shares his optimism concerning SWPF testing. Mr. Janssen favors WPF tests and worries about potential flaws in SWPF methods.

"The problem with SWPF studies is that we don't know how they correlate to performance in the real world," he says. "Right now, I don't think anyone knows how to do that--how to make the correlation. When you look at the results of a workplace study and compare those to the results of a simulated workplace study on the same respirator--in this case, I am talking about loose facepieces--they differ by an order of magnitude. Nobody knows what happens in the workplace that accounts for that. If you knew that, and you could make a simulated study incorporating that condition, then you might have something."

ANSI's standard, Z88.2-1992 (which was also discussed at the roundtable), used, in part, the method Mr. Janssen advocates in determining APFs. To formulate its own table, the standard used WPF testing information when it was available for specific types of respirators and other types of data when it was not. WPF tests are very similar to SWPF studies. The difference is that, with WPF studies, there is no simulation. The person wearing the respirator is performing actual job tasks. WPF results indicate a clear difference between loose-fitting facepieces and hoods and helmets. These results were not found in many SWPF studies.

As promising of WPF tests are, they do have limitations that cause safety professionals some concern. "A lot of them are impractical; they're expensive. It's hard to find work sites with the appropriate atmosphere and contaminants at a high enough level to test a high-end respirator," says Mr. Janssen. "We really don't know that a workplace study in one plant is completely applicable to different plants. Logic says it should be."

Some industry experts question any of the current APF data. When asked whether, given the current APF tables available to safety professionals, inclusion of APFs in the respirator standard was necessary, Mr. Newcomb and Mr. Vincent answered firmly. "Yes. NIOSH's tables are over two decades out of date. ANSI's [APFs] are not enforceable. OSHA's [APFs] are inconsistent throughout their substance specific regulations."

Mr. Newcomb and Mr. Vincent's comments bring to light what is seen as a major obstacle in determining proper APFs to be included in a federal standard. Many of the APF tables now on record do not agree with one another. OSHA indicates that, until the standard is modified, it "will recognize the APFs declared in its substance-specific standards, if applicable, or APFs granted by a specific OSHA interpretation, or the NIOSH APFs." The trouble is, NIOSH and OSHA have different APFs for some of the same respirator classes. This is due, in large part, to the tests and data analysis used to determine the APFs. As Mr. Janssen indicated following the roundtable discussion, SWPFs, WPFs, and SPFs all have multiple testing methods that can produce any number of results. Because there is no standardized way to interpret the end data, discrepancies can appear even if two tests were conducted with the same format.

Standardization was a rallying cry for many industry leaders coming out of the roundtable--no matter which testing method is judged to be the best. But with a lack of consensus, is there any place for safety professionals to find reliable APF data?

Comprehensive Program Still Needed
With very few alternatives, the industry is turning to the ANSI standard, which was not acknowledged by OSHA, and to respirator manufacturers themselves. "Generally, we prefer to follow the ANSI standards because we know those have been tested." says Lisa Mork, product manager for Survivair.

"There is no information that has been published and peer-reviewed that has shown the ANSI APFs are wrong," says Mr. Janssen. "Every time there has been a workplace study done, the ANSI assigned protection factor is supported."

Regardless of how useful the ANSI standard is any APF table would have to pass through OSHA's lengthy review process. The question is, do manufacturers, safety organizations, respirator users, safety professionals, and, most importantly, OSHA, use the ANSI APFs, or do they develop a new standardized method for developing a brand-new APF table?

Most are unsure of OSHA's direction. "I know that significant work had been done on formulating APFs within OSHA, but that was under different leadership," says Ms. Bradley, referring to Mr. Henshaw's recent confirmation to replace Charles Jeffress as head of OSHA. "Some of the key people who worked on APFs have been relocated or do not work for OSHA any longer."

Ms. Bradley went on to say that ISEA is "encouraging OSHA to proceed with APF rulemaking and hopes that it considers the industry consensus standards that are available to them and are being used today." However, it is no secret that ISEA hopes the ANSI standard would be adopted. Ms. Bradley indicates that ISEA believes the ANSI standard should be "the template, since the numbers included in the standard are scientifically sound."

Not all industry leaders agree with Ms. Bradley, though. At the recent roundtable concerning APFs, participants agreed that different tests--including SWPFs, SPFs, and WPFs--should be compared against each other in determining new APFs. More importantly, according to the participants, standardized testing methods, data collection, and data analysis must be implemented in order to arrive at more reliable results. The roundtable urged OSHA to use all data available in forming its APF table, according to an article by Mr. Janssen published afterward by the American Industrial HygieneAssociation's Synergist magazine.

Table of APFs for Various Types of Respirators
Respirator Class/Type
OSHA
(cadmium std.)
NIOSH

Air Purifying
Filtering Facepiece
Half-Mask
Full-Facepiece


10
10
50


10
10
50

Powered Air Purifying
Half-Mask
Full-Facepiece
Loose-Fitting Facepiece
Hood or Helmet


50
250
25
25


50
50
25
25

Supplied Air
Half-Mask-Demand
Half-Mask-Continuous
Half-Mask Pressure Demand
Full-Facepiece Demand
Full-Facepiece Continuous Flow
Full-Facepiece Pressure Demand
Loose-Fitting Facepiece
Hood or Helmet


10
50
1,000
50
250
1,000
25
25

10
50
1,000
50
250
1,000
25
25
Self-Contained Breathing Apparatus
Demand
Pressure Demand


50
>1,000


50
10,000

Industry leaders may be divided as to how new tables should be formulated, but most are ready to agree action is necessary. Reliable APFs are critical "because they provide guidance as to the level of protection that each class of respirator can be used to [provide]," says Ms. Bradley.

APFs are fundamental elements in aiding IHs as they choose a proper respirator for a hazardous job. But industry leaders are quick to point out that those numbers are meaningless if employees are not trained to use respirators properly. While it is required that all workers who wear respirators be trained concerning the fit and limitations of respirators, many times they are not even aware of APFs. Those concerns are left up to the safety professionals and industrial hygienists. But if a worker is not wearing a respirator properly, any new APF table is not going to keep a worker safe, some say.

"The user does need to know that the level of protection is dependent upon the proper fit of the respirator to the individual, even though the respirator has an assigned protection factor," Ms. Bradley says. "An APF does not automatically mean that a particular respirator will provide that level of protection on a particular individual without all necessary elements of a comprehensive protection program."

OSHA has not, as of yet, given any indication as to how it might go about including an APF table into the standard. Whether it looks at adapting the ANSI standard, adopts another APF table, or looks to standardize a new method of testing, data collection, and data analysis, the process will almost certainly involve a comment period followed by the usual steps in promulgating a standard. The result is that any addition to the standard is likely to take more time. For safety professionals and manufacturers, who crave reliable information and data that can help protect workers from harmful conditions, any movement to include APFs in the federal standard will not come fast enough.

Reproduced with permission from Occupational Safety and Health magazine.



Suppliers | Products | Experts | News | Articles | Calendar | Process Zones

The Voice of the Finishing Industry Since 1936 Copyright © Gardner Business Media, Inc. 2014

Subscribe | Advertise | Contact Us | All Rights Reserved