Epoxy Resins

About epoxy resins

In a composite part, the resin binds the fibres together, allows loads to be transferred between the fibres and provides a barrier to weather, water or chemicals.

Epoxys are usually sold as a two-pack system – Part A (resin) and Part B (hardener). Part A is the epoxy resin and there are many different types available. Diglycidyl ether of bisphenol A (DGEBA) is one of the most common resins used and is also written as bisphenol A based epoxy resin. Other types of epoxy resin can also be mixed in as a blend and other components added to give the required properties. While there are various hardeners, one of the main types is described in the section on polyamine-based hardeners.

Epoxy resins supplied to the composites industry contain various additives. These may include any one of the following: thixotrope, pigment, filler, UV absorbers and fire retardant. Unlike polyester and vinyl ester resins, epoxy resins are not dissolved in styrene monomer. Epoxy resin and hardener are both supplied as liquids. When they are mixed, they react and crosslinks are formed between the two chemicals. When some of the crosslinks have formed, the system forms a gel and is said to be “gelled”. When most of the cross-links have formed, the system forms a solid and is said to be “cured”.

If epoxy resins come into contact with the skin, sensitisation can occur. This can occur after short or long term exposure to epoxy resin. Once a person has become sensitised to epoxy resin, any future exposure results in an allergic response. Effects include dermatitis of the skin and redness and irritation of the skin and eyes, even with minimal exposure.

Special Protection Information

Respiratory Protection: Adequate ventilation should be provided. If above the NOHSC exposure standard, use SA approved respiratory protective equipment. If dust is generated during cutting or machining/grinding/sanding of cured product, wear disposable dust mask (Type P1) or better as determined by your risk assessment. When using resin system with fibres, use combination mask with vapour and dust article filter.
Eye Protection: Use SA approved chemical splash goggles.
Protective Clothing: Wear chemical resistant gloves such as butyl rubber or neoprene rubber gloves. Apply barrier creams to un-covered skin. Wear full length trousers and long sleeved shirts and safety boots.
CONSULT SAFETY EQUIPMENT SUPPLIERS FOR RECOMMENDATIONS.

Effects of Exposure

Eyes: May cause mild irritation and redness.
Inhalation: Irritation of the upper respiratory tract is not usually associated with the use of epoxy resins, unless heated.
Skin: Prolonged and/or frequent contact can result in irritation of the skin. Epoxy resins are known to cause sensitisation of the skin.
Swallowing: Epoxy resins are usually not of any concern with respect to toxicity. However, some formulated epoxy resins may become of concern with respect to toxicity due to the inclusion of other chemicals which are of greater toxicity.

First Aid Procedures

Eyes: Flush with water for at least 15 minutes.
Inhalation: Remove to fresh air. If breathing is difficult, seek immediate medical assistance.
Skin: Remove contaminated clothing for laundering. Wash with soap and water. Do NOT use solvents.
Swallowing: Do NOT induce vomiting. If person is conscious, they should drink large quantities of water. Seek medical advice immediately.

Spill or Leak Procedures

Eliminate all sources of ignition and ventilate area. Wearing protective equipment, stop spill at source, dam area and ifpossible pump liquid into salvage tank. Alternatively, absorb residue with vermiculite or sand. Scoop up using non-sparking tools into labelled waste container. Dispose of waste in accordance with local, state and federal regulations. Reporting of leaks/spills may be required under EPA and Dangerous Goods regulations.

Fire Extinguishing Procedures

Wear protective clothing and equipment including self-contained breathing apparatus. Use water, mist, foam, carbon dioxide or dry powder to put out fires. Cool fire exposed containers with water spray.

Storage and Handling Procedures

Store in properly closed, labelled containers in a cool, well ventilated area. Keep away from strong oxidising agents. Do not transfer to unmarked containers.

KEY to abbreviations – CNS: Central Nervous System EPA: Environmental Protection Authority NOHSC: National Occupational Health & Safety Commission (Worksafe Australia) PVC: Polyvinyl chloride SA: Standards Australia

Disclaimer: Facts and information reported on this page are believed by Composites Australia to be accurate at the date of printing. No responsibility is accepted by Composites Australia for the use or misuse of information on this page. Composites Australia accepts no responsibility for damage or injury caused by information or omissions contained on this page.