When re-certifying an employee in his or her own facepiece, you may occasionally encounter a situation where a respirator visually appears to fit well, but fails the initial fit testing exercises. While there are many reasons for an employees facepiece to fail (changes in body weight, damage to the facepiece, etc.) it may be difficult to uncover the source of the leak. In these cases where it is obvious the testing must stop, the operator is then responsible for finding the source of the leak. One effective way to trouble shoot the problem when using the TSI PortaCount is to utilize the Real-Time Fit Factor Display included with the fit testing software. With the facepiece connected to the PortaCount in the usual manner, the operator can observe a display of the fit factor in near real time as a vertical bar graph. To trouble shoot the problem, begin by having the subject re-position the facepiece and/or adjust the headgear. If this doesn't improve the fit factor, try covering various potential leak sites. Sometimes the tubing connector itself becomes a leak site. If this is suspected, use a scissor to snip away a quarter inch of tubing and try again. If the real time fit factor display shows an improvement, you may have solved the problem. If not, eventually a persistent and competent operator will be able to identify the leak site. The advantage of the real time display is that the fit factor is displayed almost immediately, allowing the operator to trouble shoot the problem quickly and easily. This is often easier than waiting for the results of an entire fit testing exercise maneuver. Keep in mind that the real time display has a lag time of approximately 15 seconds, so the changes made will have a short delay before seeing the results. None the less, this handy feature is a great way to trouble shoot leaks with the TSI PortaCount. So where is the real time display? Look at the PortaCount tool bar at the top of the screen. It's the icon with a small vertical bar colored in blue. It's just to the right of the man wearing a half mask respirator (fit test icon) and to the left of the daily check icon (the one with the large check mark). Try it the next time you have a leaking facepiece. It may save you some time and show off your detective skills.
OSHA requires the employer to have a written policy for changing out cartridges used for protection against gases and vapors. OSHA also requires the employer to include (in writing) the data or rational used to support the written change out policy. Relying solely upon odor and/or taste is not acceptable practice and may lead to an OSHA citation. Worse yet, an allegation regarding an unacceptable change out policy may lead to an even more costly lawsuit. So where does OSHA make this statement? Go to 1910.134 (d)(3)(iii)(B)(2) where it states:
"If there is no ESLI appropriate for conditions in the employer's workplace, the employer implements a change schedule for canisters and cartridges that is based upon objective information or data that will ensure that canisters and cartridges are changed before the end of their service life. The employer shall describe in the respirator program the information and the data relied upon and the basis for the canister and cartridge change schedule and the basis for the reliance on the data."
N95 filters have been around for nearly a decade, yet it is amazing how these filters are so poorly understood. Specifically, I'm referring to the incorrect use of the term "N95 respirator". An N95 respirator could be a certain type of filtering facepiece respirator, however, it could also refer to an elastomeric (rubber) half mask or full facepiece respirator. So when you read an article or hear a speaker refer an N95 respirator it's not clear what type of respirator is being worn. N95 refers to a specific type of NIOSH-approved respirator filter. This filter could be attached to an elastomeric half mask facepiece or other respirator. Likewise, when a worker wears a filtering facepiece, it could be an R or P series filter and not an N series filter. So we can't assume, all filtering facepieces are of the N style either. So in the future, when someone refers to an N95 respirator, ask them what type of respirator they are referring to. In many cases they are probably referring to an N95 filtering facepiece, but we can't assume this to always be true. One day I hope journal articles will require correct use of respirator terminology so the reader clearly understands the type of respirator being referred to. In the future, we may even see proper respirator terminology used with Material Safety Data Sheets (MSDS), but don't hold your breath! Until then, we can all do our part and ask the speaker to clarify what they mean by an N95 respirator.
Approximately 800 workers with responsibility for cleaning up debris at the World Trade Center have filed a class action lawsuit against the leaseholder of the World Trade Center and four construction companies hired to oversee removal of debris after collapse of the twin towers. The essence of the lawsuit is a claim that those with responsibility did little to protect workers from toxic dusts including glass and asbestos fibers, diesel exhaust, and other chemicals. The claim is based upon an allegation that the defendants should have recognized the need to protect workers with respiratory protective equipment. When respirators were accessible the claim alleges a lack of respirator training, thus those who did have respirators were not taught how to properly wear them. Basically, this lawsuit is similar to others where the allegation is made that a hazard exists, yet the employer failed to provide respiratory protective equipment, appropriate training and/or select the appropriate type of respiratory protective equipment.
Respirators are worn to reduce workplace exposure to toxic dusts, fumes, mists, vapors, and gases. When respirators are not properly worn, used, selected, fitted, and maintained, disease may result. With respect to respiratory diseases, occupational asthma once again tops the list as the most commonly acquired occupational respiratory disease in the US and most other industrial countries. There are only a few countries where occupational asthma does not top the list and these are countries where mining is extensive. In the US, it is estimated that up to 15% of adult asthmatics can trace their asthma back to their jobs. While these estimates do vary to some degree, it does make occupational asthma a considerable concern. Occupational lung disease (including asthma) is the number one cause of work-related illness in the US. Engineering controls and respiratory protective equipment could prevent this. In many cases, employers have not conducted an appropriate hazard assessment and/or selected respirators appropriately.
On November 18, 2004, John Henshaw (assistant secretary of labor) released the agency's annual enforcement statistics. For fiscal year 2004 (FY04), OSHA exceeded its inspection goal with 39,167 inspections and 86,708 violations of OSHA standards and regulations. This represents an increase of 3.8 percent over the previous year and nearly 10 percent over the last 5 years. Of greater significance was the increase in serious and willful violations. Violations of the respiratory protection standard remain high. Here's the top five violations of the Respiratory Protection standard (1910.134):
OSHA recently released a Safety and Health Information Bulletin regarding deaths with use of air-line respirators (see reference below). It's hard to believe this still happens, but it does. In the OSHA bulletin they briefly describe five (5) case histories where deaths occurred due to incorrect coupling compatibility and inadequate supervisor oversight that were major factors that contributed to the delivery of non-respirable gas to the respirator wearer. Air-line respirators are typically used in a variety of workplace settings including painting, cleaning, manufacturing, abrasive blasting, and others. They may be attached to hoods, helmets, full face, or even half mask style facepieces. When connected to half and full facepiece respirators, they must be fit tested. When there is insufficient oxygen in the delivered gas supply, the worker will not feel the sensation of breathlessness, Consequently, they are fooled and don't recognize that something is wrong. The victim may quickly blackout and die without any warning. When airline respirators are connected to inert gas lines without Oxygen, unconsciousness can occur in seconds. Use this as a reminder to review your written respirator program and training programs. Make sure the couplings are incompatible with other fittings at the worksite. Also check to ensure the fittings of an airline respirator are tested and approved by NIOSH. Its also important to check to ensure that breathable air systems are not interconnected to non-breathable air systems. For information about this OSHA Safety and Health Bulletin, go to the OSHA web site www.OSHA.gov and search for "SHIB 04-27-2004". The title of the article is: Deaths Involving the Inadvertent Connection of Air-line Respirators to Inert Gas Supplies.
On December 6, 2004, the Federal Register (Vol 69, No. 233) published a request for public comment on draft Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-care Settings, 2005. On November 30, 2004, CDC/NIOSH held a two-day workshop in Atlanta to discuss this topic. At this workshop, Dr. McKay presented a paper on the Evaluation of Respirator Fit Test Methods and participated on a panel discussion on respiratory protection. It became apparent that many hospital infection control programs continue to misunderstand respirator fit test methods used for N-95 filtering facepiece respirators. For example, a recent editorial in a respected journal incorrectly described a fit test method where employees wearing filtering facepiece respirators would smell odors from jars containing banana oil! During the CDC workshop it also became apparent that many infection control programs have not fully appreciated the value of quantitative risk assessments to help identify when and where respirators should be worn. Many programs would rather change time-proved respiratory protection guidelines than tackle the need to conduct a quantitative risk assessment. It was also unclear if hospitals have considered an acceptable level of risk for their employees. The draft guidelines are available as a pdf file on the CDC web site at http://www.cdc.gov/nchstp/tb/Federal_Register/default.htm. If you have an opinion written comments must be received by February 4, 2005.
October 2004 NIOSH released their Respirator Selection Logic (RSL) to provide guidance to respirator program administrators. The RSL is not intended to be used for selection of respirators for protection against infectious agents or for chemical, Biological, Radiological, or Nuclear (CBRN) agents of terrorism. When the OSHA standard on APFs is finalized, NIOSH intends to consider revisions to the RSL. It is important to recognize that the RSL identifies classes of respirators that provide a minimum level of protection against a chemical at a given concentration, however, it does not identify individual respirator models. The respirator program administrator must still take into account other user and workplace factors to select a certain style respirator to match the needs of the employee. For additional information go to the NIOSH web page at http://www.cdc.gov/NIOSH.
On September 14, 2004, the British Occupational Health Research Foundation released an excellent document providing evidence-based guidelines for the prevention, identification, and management of occupational asthma. The evidence review and the 22 recommendations derived from it are designed to provide a robust approach to the prevention, identification, and management of occupational asthma, based upon the best available medical evidence at this time. While I've only had the opportunity to skim through this comprehensive document, I highly recommend it to anyone with an interest in occupational asthma. To get your free copy, go to: www.bohrf.org.uk/content/asthma.htm
Roy McKay, Ph.D.
Course Director
University of Cincinnati
www.DrMcKay.com