WHAT IS CARBON FIBER?
Carbon fiber is a material literally made up of small fibers of carbon. These small fibers were found to be exceptionally strong individually, but when thousands of these fibers are woven and bonded together under extreme heat, they are stronger than steel. Carbon fiber is the strongest, man-made material in the world. It is incredibly lightweight and will not stretch. It can be woven into fabric sheets or melted down and molded into various shapes to create hundreds of different products. The process to make carbon fiber is complicated and was originally very expensive. Since it was so expensive, for years carbon fiber was only reserved for critical applications like space shuttles, airplane wings, and bridge repairs.
HEALTH EFFECTS OF CARBON FIBER EXPOSURE
The principal health hazards of carbon fiber handling are due to mechanical irritation and abrasion similar to that of glass fibers. Carbon fibers are easily broken by stretching (by less than 2% elongation); the fibers can easily become a fine dust during cutting, machining or mechanical finishing and can then be released into the surrounding atmosphere. These micro fibers if uncontrolled have a potential to stick into human skin or the mucous membranes causing irritation.
HEALTH EFFECTS OF SOLVENTS USED IN CARBON FIBER MANUFACTURE
Most fibers have a coating that can also cause chemical irritation (called a 'sizing' which is often an epoxy or other resin) . Many of the solvents used in advanced composite processes are volatile, flammable and irritating to skin and eyes. Health effects typical of these chemicals include irritation of the eyes and upper respiratory tract, dizziness, drowsiness, nausea, and vomiting. Visual disturbances may also occur. Repeated or prolonged skin contact with these liquids may cause dermatitis. Material Safety Data Sheets (MSDS) must be consulted before the use of the particular solvents and or resins with the carbon fiber product and all precautions outlined in the MSDS should be implemented.
After curing, fibers become very rigid and may protrude from poorly machined or fractured surfaces. Such surfaces should be handled with care, due to the potential for laceration and impregnation of fiber splinters into the skin. Heavy style gloves should always be worn when handling materials to protect against penetration of these fibers as well as contact with resins. Protection of eyes and throat from carbon fiber dust is paramount. Users must wear full goggles and a dust mask to prevent dust inhalation. Dust particulate masks must be fit tested to the individual. Protective clothing should be worn whenever dust is created (such as while machining). The use of elastic cuffs on the protective clothing will keep dust from getting inside protective suits.
SAFE WORK PRACTICES
Employees using carbon fibers or composites must be trained in its use.
- Tasks involving dry machining of carbon fibre must be undertaken using an appropriate extraction or ventilation system.
- Tasks involving the use of solvents and resins must be done in conjunction with MSDS requirements. This includes using in a well ventilated areas, a fume cupboard or spray booth.
- When machining of carbon fiber, minimize dust or particulate generation by:
- • Wet processing of the material - see electrical safety
- • Using non-powered hand tools
- • Cutting the material while still 'green' or partially cured.
- Emergency eyewash stations and hand washing facilities must be available for each work area.
- A first aid kit must be available for each work area.
- All skin and eye contact must be avoided.
- Student and staff exposure may also be controlled by scheduling operations with the highest exposure risk at a time when the fewer people are present however within normal business hours.
PERSONAL PROTECTIVE EQUIPMENT (PPE)
TGloves, protective clothing, and eye protection is mandatory due to the nature of working with composite materials. Selection of appropriate protective equipment should be based on the type of task being undertaken and the associated hazards.
- Protective clothing should cover of the entire body to avoid exposure to carbon fibres or resins and solvents, eg. Tyvek Suit
- Eye protection can be provided by standard safety glasses with side shields for non-machining work. Goggles or a combination of a face shield and glasses is required for machine-based work.
- Gloves: regular latex or nitrile disposable gloves can be used with carbon fibre materials. Heavier gloves are more appropriate when fibre splinters are a concern. When using solvents or resins the material safety data sheet should be referred to for the appropriate glove type.
- Respiratory protection is required where:
- • Airborne solvent or dust may be present or 'off-gassing' is occurring.
CONTAMINATION OF PPE AND CLOTHING
Following any contamination of clothing with carbon fibre or resin solutions, remove the garments and dispose of as waste (see below). PPE may be washed under running water; disposable gloves are to be discarded after contamination.
Cured or raw carbon fibre waste should be regarded as 'Industrial Waste' double bagged and disposed of through the regular waste stream. Fine waste such as dust and loose fibres may be disposed of in a similar way however, care needs to be taken in collection and PPE must be worn. Chemical waste must be disposed of as prescribed waste through a licensed contractor such as Chemsal.
Skin: Irritation and rashes - Wash under cold or warm water with soap or use sticky tape to help remove the fibers from the skin.
Eye: After removing contact lenses if any, wash eyes with clean running water for approx. than 15 minutes. Remove contact lenses if worn before washing. Seek medical assistance.
Ingestion: Wash out mouth immediately with clean fresh water. Seek medical assistance.
Inhalation: Dusts and fine fibers are documented as being respirable, and embed into mucous membranes causing irritation. Remove person to fresh air and seek medical assistance10. Spills of solvent materials or resins must be cleaned up immediately using local or building spill kit to MSDS directions.
**Content found by different university sources.