Personal protective equipment
Selection of appropriate equipment is based on professional expertise and common sense. Even the U.S. government’s Occupational Safety and Health Administration (OSHA) has produced guidelines for the selection of PPE and are found in Title 29, Code of Federal Regulations (CFR) 1910, Subpart I Appendix B of the OSHA Standards.
The first step in determining suitable PPE is to survey the area and determine the possible hazards. Some examples include:
• Mechanical impacts
• Penetration by sharp objects
• Roll over by heavy objects
• Harmful Dust
• Electrical hazards
• Motion hazards
• Biological contaminants
Once the different types of risk are assessed, the level of risk should then be considered. What’s the likelihood for something to go wrong?
Exposure to toxic substances are all but unavoidable in this business and in many cases, those being exposed are unaware of the potential danger. Frequently in aircraft maintenance, exposure to several hazards simultaneously are likely. For example, during a complete avionics refurbishment on an older aircraft, the technicians were required to remove plumbing used to deliver hot engine bleed-air to the air-conditioning systems as well as noise-deadening mats throughout the cabin. These air-pipes were wrapped in an insulating blanket made of asbestos and the noise suppression devices fabricated from lead. It should be of utmost importance to know the materials you’re working with.
Popular cleaning solvents such as Methylethylketone (MEK) can be unhealthy if appropriate protections are not observed.
Adhesives can also pose a significant risk and the Material Safety Data Sheet (MSDS) 3M 1300L recommends to "avoid prolonged breathing of vapors" and to select a half-mask organic vapor respirator will working with and around this substance. Even working in a confined space in the presence of a hydraulic mist can cause serious health problems. Mineral-based hydraulic fluids can cause vomiting accompanied by pneumonitis.
Breathe easier with proper respirators
Respirator selection is best made by first determining the type of exposure. Items to be considered are the type of contaminant. Is it dust, fumes, mist, gas or a vapor? If it is a chemical, is an MSDS available? Other factors that will help determine the type of respirator used include:
• Type and amount of hazardous exposure
• Knowledge of respirators and their relevant characteristics
• Job Site
• Personal medical characteristics
Job site is one factor in aircraft maintenance that many of us have no control over. Many large commercial aircraft have immense, well-ventilated avionics compartments as well as access doors that allow ample admission to the area forward of the main instrument panel. For those of us in general aviation, the job site could be anywhere from a heated and/or air-conditioned hangar to a remote location in some far off corner of the world. In most cases, those of us involved in avionics maintenance will at some point in our career find ourselves in some tightly constrained area where it may be possible to see your target with one eye, while still getting two fingers in to accomplish the task at hand. Situations such as this may have an impact on respirator or other PPE selection. Personal medical conditions are another major consideration when selecting a breathing apparatus.
There are three categories of Respirator and they include: Air Purifying, Supplied Air, and Self-Contained Breathing Apparatus (SCBA).
Air-Purifying Respirator – contains filters or canisters that remove contaminants by passing the ambient air through the air-purifying element before it reaches the user. These devices can capture dust, mist, and fumes but provide no protection against gases or vapors. Those involved in health care have a special Air-Purifying Particulate Respirator that will reduce the wearer’s exposure to blood and body fluids.
Atmosphere-Supplying Respirators – deliver clean air to the user from a source other than the air surrounding the wearer. An Air-Purifying Combination Respirator will provide protection against ingress of particulates as well as gas and vapors, whereas an Air-Purifying Gas/Vapor Respirator does not protect against airborne particulate, but does use chemical filters to remove gas and vapors. Air-Supplied Respirators use a hose and an external and remote compressed air source and are effective against most contaminants, but the drawbacks include bulk and possible restriction to movement in confined space. Combined Air-Supplying and Self-Contained units that have a backup air tank in the event the primary external air source fails, but this type may limit mobility.
Self-Contained Breathing Apparatus (SCBA) uses a fully mobile Clean-Air Supply Pack that is worn by the user. While it increases mobility, maneuverability in tight areas may be reduced.
In addition to proper equipment selection, an equally important factor is proper fit. After all, if a breathing apparatus fails to prevent contamination, it is not providing the user with the level of protection that was intended. Facial hair such as a beard may restrict the user from all but a full-hooded, Air-Supplied type device. Of course, those exposed to electrical devices will want to ensure that their PPE will not subject the wearer to any additional danger.