Standard Practices for Working with Fiberglass
Fiberglass is one of the most useful manufactured products in industry, with numerous commercial applications. It is a man-made fiber used primarily in the production of insulating materials and for reinforcing plastics and composites. Various products ranging from home insulation materials to boats are composed of fiber glass. Its physical properties make it ideal for structural building materials because it is inert, lightweight, heat resistant and a very strong fiber. These same properties are also responsible for some of the hazards encountered in the workplace.
Depending on the size and dimensions of the fiber measured in the environment, you will find different biological effects on humans. Smaller glass fibers, generally less than 3.5 microns in length, can be inhaled and deposited in the lung where they can accumulate and cause fibrotic changes, while larger fiber glass fibers cause skin irritation due to mechanical action. It is both the inhalation and dermal hazards that give fiberglass a greater hazard potential than nuisance dust and require appropriate protective equipment to minimize exposure. The purpose of this paper is to review the potential hazards of working with fiberglass, assess the risk and provide a recommended best practice.
Since there are numerous uses for fiberglass, one needs to identify the other hazards associated with the production of fiberglass products in order to determine and control the greater hazard. Generally, the principles involved are similar for most hazardous substances and basically involve following good industrial hygiene practices. Various trade organizations have developed and published their own specific guides and work practices and should be consulted for reference. For the purpose of this paper, fiberglass will be considered the primary hazard and the best practices will be limited to general principles.
As was mentioned before, small fiberglass fibers can be inhaled and therefore are an inhalation hazard, but the primary hazard associated with fiberglass is skin irritation. Respiratory protection devices are not needed for fiberglass exposures below the recommended environmental limit (ACGIH TWA 10mg/m3), but for situations where airborne concentrations may exceed the limits recommended, respirators approved by NIOSH may be used, but not as a substitute for feasible engineering controls on general fiber glass exposure.
The primary health effect and hazard associated with larger fiberglass fibers involve skin and eye irritation. Most skin problems arise from direct contact with fiber glass through handling rather than from airborne fibers or dust. Decisions on whether to wear gloves or other protective clothing will depend on the nature of the work as well as the nature of the materials involved. In general, wearing gloves and other items of protective clothing such as booties will prevent fiberglass from contacting exposed skin surfaces and street clothes worn underneath. Fiberglass can and does adhere to street clothes and shoes where it is retained in fabrics and bonded to shoes if adhesives are used in production processes to make fiberglass composites. If these street clothes and shoes are not removed and laundered at work, they are brought home contaminated with fiberglass which in turn will contaminate household family laundry.
Eye irritation is another hazard associated with working with fiberglass, particularly when installing fiberglass insulation materials overhead. Safety glasses or goggles will prevent contact with the eye and alleviate potential eye injuries from fiber glass. It should also be noted that in many applications and processes fiberglass is bound with adhesives and in plasticizers, where it becomes rigid and sharp.
These sharp glass fibers then can act like a razor blade, causing cuts and lacerations, particularly when cutting fiberglass products or when removing them from molds.
Because of the diverse use of fiberglass in manufacturing operations, there is no one main occupational disease associated with working with fiber glass. Epidemiological studies have not determined that there is a substantial risk of lung injury resulting from the inhalation of small fiberglass fibers, even though fibrotic changes in lung tissue have been observed in some occupations working exclusively with the production of fiberglass. However, large fiberglass fibers can and do cause irritation to the skin and eye. The irritation is primarily due to the mechanical abrasion of fiberglass on wet sweaty exposed skin. Repeated exposures to the skin cause additional irritation, redness and itchiness. In some cases individuals develop tough skin as a result of continued exposure and become immune to fiber glass irritation. Individuals who work intermittently with fiberglass tend to develop irritation repeatedly after each exposure. Therefore, these acute exposures that repeatedly cause irritation tend to be the major risk involved with handling fiberglass.
The best practice to follow when working with fiberglass is to prevent and avoid skin contact. Inhalation of small fiberglass fibers is not a major concern if airborne fiber concentrations are below recommended environmental limits. Respirators should be worn if concentrations exceed this limit and if other airborne contaminants produced in the process exceed recommended exposure limits.
Protection from skin exposure to the glass fiber is best achieved by wearing appropriate protective equipment such as gloves, suits and boots if necessary. A hazard assessment should be made in accordance with OSHA's personal protective equipment standard to determine the appropriate protective clothing and procedures to be followed. This would include wearing gloves, suits and booties that prevent skin exposure. These items of clothing should be worn over regular street clothes and disposed of or removed at the end of the work day to be laundered if they are going to be worn again the next day. Workers should have access to lockers and a shower and wash basin where they wash away fibers from contaminated body surfaces.
In general good industrial hygiene practices should be followed, such as utilizing engineering controls to reduce airborne exposures and good housekeeping to keep fiberglass contained in work areas. A separate lunchroom or area should be designated for eating and drinking. Eye glasses or goggles should be worn to prevent eye exposures, and an eye wash and safety shower should be readily accessible. Since cuts can occur from handling bonded fiberglass, first aid kits should also be readily available. Finally, waste bins or cans should be located in work areas to dispose of excess unused fiberglass.