05 Jul Chemical Hazards – Composite Safety

Chemical Hazards – Composite Safety

Composite manufacturing and repair can expose employees to hazardous chemicals, vapors, fibers, dust, and particulates. Common materials include resins, catalysts or hardeners, fiberglass, carbon fiber, aramid fibers such as Kevlar, and structural core materials. Employees shall understand the hazards of the specific products they use and follow the product Safety Data Sheet (SDS), manufacturer instructions, and established safe work procedures.

Common Composite Materials

Composite operations may involve:

• Resins: Epoxy, polyester, and vinyl ester resins.
• Catalysts and Hardeners: Methyl ethyl ketone peroxide (MEKP), benzoyl peroxide, and epoxy curing agents or hardeners.
• Reinforcement Materials: Fiberglass, carbon fiber, Kevlar or other aramid fibers.
• Core Materials: Foam and other structural core products.
• Cleaning and Process Chemicals: Solvents, release agents, adhesives, coatings, and other chemicals used during fabrication or repair.

The hazards vary considerably by product. Never assume that PPE or controls appropriate for one composite system are suitable for another.

Primary Hazards

Composite manufacturing and repair may expose employees to:

• Hazardous vapors from resins, solvents, catalysts, and curing agents;
• Airborne fibers and dust generated during cutting, drilling, sanding, or grinding;
• Skin irritation, dermatitis, or chemical sensitization;
• Eye and face injuries from chemical splashes;
• Flying particles generated during machining and finishing;
• Fire hazards from flammable or combustible materials;
• Chemical reactions caused by incompatible materials;
• Respiratory irritation or sensitization; and
• Noise from grinders, sanders, saws, and other equipment.

Employees shall review the SDS before using an unfamiliar chemical or composite material.

Personal Protective Equipment

PPE shall be selected based on the hazards identified by the employer’s hazard assessment, the SDS, and the specific operation being performed.

Do not select gloves or respirators solely by material category. Chemical compatibility, breakthrough time, airborne concentration, and the specific product being used must be considered.

Eye and Face Protection

Chemical catalysts and hardeners can cause serious eye injuries. Grinding, sanding, drilling, and cutting can also generate high-speed particles.

Employees shall:

• Wear appropriate safety glasses or goggles for particulate hazards.
• Wear chemical splash goggles when handling chemicals capable of splashing.
• Use a face shield over appropriate eye protection when significant splash or flying-particle hazards exist.
• Never rely on a face shield alone as primary eye protection.
• Immediately flush the eyes following chemical exposure in accordance with the SDS and emergency procedures.

Required emergency eyewash facilities shall be readily accessible where corrosive materials could contact the eyes.

Skin Protection

Resins, hardeners, catalysts, solvents, and other composite chemicals may cause irritation, burns, dermatitis, or sensitization.

To minimize exposure:

• Avoid direct skin contact with uncured composite chemicals.
• Select gloves based on the SDS and chemical compatibility information.
• Replace contaminated, damaged, or degraded gloves.
• Wear appropriate protective clothing.
• Remove contaminated clothing promptly.
• Wash exposed skin thoroughly with soap and water.
• Do not use solvents to clean resins or adhesives from the skin.
• Wash hands before eating, drinking, smoking, or leaving the work area.

Grinding, Sanding and Cutting

Grinding, sanding, drilling, sawing, and machining cured composite materials can release fine dust and fibers into the air.

Whenever possible:

• Use local exhaust ventilation or dust-collection systems at the point where dust is generated.
• Use vacuum-equipped tools where practical.
• Avoid using compressed air to clean composite dust from clothing or work surfaces.
• Use HEPA-filtered vacuuming or other approved cleaning methods.
• Wear appropriate eye and skin protection.
• Use respiratory protection when required by the exposure assessment.

Carbon-fiber dust may also be electrically conductive and can create problems if allowed to accumulate in or around electrical equipment.

Respiratory Protection

Engineering controls such as enclosure, local exhaust ventilation, and dust collection should be used as the primary means of controlling airborne contaminants where feasible.

When respiratory protection is required, employees shall use only respirators selected for the specific contaminant and exposure conditions. Employees required to wear respirators must participate in the company’s Respiratory Protection Program, including required medical evaluation, training, and fit testing for tight-fitting respirators.

A generic “organic vapor” or “dust” respirator should not automatically be assigned to all composite operations. The SDS, exposure assessment, contaminant type, concentration, and applicable exposure limits must determine respirator selection.

Chemical Handling and Storage

Composite chemicals shall be properly labeled, handled, and stored.

• Keep containers closed when not in use.
• Store chemicals according to the SDS and manufacturer requirements.
• Segregate incompatible chemicals.
• Keep flammable materials away from ignition sources.
• Maintain adequate ventilation in mixing and application areas.
• Use appropriate dispensing and mixing equipment.
• Clean spills promptly using established spill-response procedures.
• Dispose of contaminated materials and chemical waste properly.

Special care shall be taken with reactive catalysts and hardeners such as MEKP and organic peroxides. They shall be stored and handled strictly according to manufacturer and SDS requirements.

Training

Employees working with composite materials shall receive training appropriate to their assigned tasks, including:

• Chemical and physical hazards of the materials used;
• SDS and product-label information;
• Required engineering controls and ventilation;
• PPE selection, use, limitations, and care;
• Respiratory hazards and respiratory-protection requirements;
• Safe mixing, application, cutting, sanding, and grinding practices;
• Chemical storage and incompatibilities;
• Spill and emergency procedures;
• Fire prevention; and
• Proper disposal and housekeeping practices.

Remember

Composite materials can present hazards before, during, and after curing. Know the product, review the SDS, control vapors and dust at their source, wear properly selected PPE, and never assume that one type of glove or respirator protects against every composite material.