About cobalt 6%
Cobalt 6% is an abbreviation for the compounds cobalt napthenate and cobalt octoate, usually supplied as a 6% solution. These compounds are promoters used in the curing of polyester and vinyl ester resins with methyl ethyl ketone peroxide (MEKP) type catalysts. Promoters are also called accelerators. They can be added to the resin by the supplier, in which case the resin is said to be pre-promoted. Alternatively, promoters can be added by the manufacturer prior to adding catalyst to the resin.
The purpose of cobalt-based promoters is to speed up the curing reaction of polyester and vinyl ester resins and allow them to cure at room temperature. The cobalt-based promoter helps the catalyst to start the chemical reaction between the resin and styrene monomer and form a cured solid.
Other types of promoters are available, including dimethylanaline (DMA). A combination of DMA and cobalt promoters can be used in conjunction with MEKP to give fast cure of polyester resins.
The exact amount of promoter added to the resin will depend on the resin used, the temperature in the workshop and the gel time desired. Usually 0.1 to 1% (based on the mass of resin) of cobalt 6% type promoter is added. Promoters must never be mixed directly with catalyst since a violent explosive reaction results. This is why it is important to ensure all promoters are thoroughly mixed with the resin before adding the catalyst.
Cobalt based promoters can be identified by their deep purple colour. Health hazards are associated with the cobalt compounds as well as the solvent (e.g. naptha) that they are dissolved in. Cobalt 6% can cause irritation of skin and eyes. It can also be toxic and is flammable.
Special Protection Information
Respiratory Protection: Adequate ventilation should be provided. If above NOHSC exposure standard level, use SA approved respiratory protective equipment.
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 uncovered skin. Wear full length trousers, long sleeved shirts and safety boots.
CONSULT SAFETY EQUIPMENT SUPPLIERS FOR RECOMMENDATIONS.
Effects of Exposure
Eyes: Can cause irritation.
Inhalation: Can cause respiratory tract irritation. Can cause headaches and uncoordination.
Skin: Can cause irritation and dermatitis.
Swallowing: Can cause stomach and bowel irritation, vomiting and depression. Aspiration of material can cause potentially fatal damage to the lungs.
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: Wash with soap and water.
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, if possible pump liquid into salvage tank. Alternatively, absorb spill with vermiculite or sand. Scoop up into labelled waste containers. Dispose of waste in accordance with local, state and federal regulations. Seek advice from supplier. Reporting of leaks/spills may be required under EPA and Dangerous Goods regulations.
Fire Extinguishing Procedures
Wear self-contained breathing apparatus and protective clothing. Use foam, dry chemical or carbon dioxide to put out fires. Cool fire exposed containers with water spray.
Storage and Handling Procedures
DG Class 3 (Flammable liquid). Keep away from heat, flame and strong oxidants. Store in closed, labelled containers in a well ventilated area. Store away from sources of ignition. Provide both floor level and breathing zone ventilation.
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.