About DMA (N, N-Dimethylaniline)
N, N-Dimethylanaline is also written as dimethylaniline and DMA. It is a promoter used in the curing of polyester and vinyl ester resins. DMA can be used on its own with benzoyl peroxide (BPO) type catalysts or in combination with cobalt 6% promoters with methyl ethyl ketone (MEKP) type catalysts. These systems give rapid cure at room temperature.
Promoters are also called accelerators. Theycan 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 DMA is to speed up the curing reaction of polyester and vinyl ester resins and allow them to cure at room temperature. The DMA helps the catalyst to start the chemical reaction between the resin and styrene monomer and form a cured solid.
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 0.05-0.6% (based on the mass of resin) of DMA promoter is added. Promoters must never be mixed directly with catalyst since a violent explosive reaction results. This is why it is important that all promoters are thoroughly mixed with the resin before adding the catalyst.
DMA is a highly toxic substance, particularly to blood, kidneys and liver, and it can be fatal if inhaled, swallowed or absorbed through the skin. Splashes can be readily absorbed through the skin and vapours can be absorbed into the blood stream. It can burn skin and eyes. The effects of DMA can also build up over time and it is a possible carcinogen.
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 PVC apron or splash suit and impervious gloves such as neoprene. Wear full length trousers, long sleeved shirts and safety boots.
CONSULT SAFETY EQUIPMENT SUPPLIERS FOR RECOMMENDATIONS.
Effects of Exposure
Eyes: Can cause burns.
Inhalation: Vapours can be absorbed into the bloodstream causing the same effects as listed below under “skin”.
Skin: Is absorbed readily through the skin causing cyanosis (first indication is blue lips and nails), headaches, dizziness, increased pulse, cardiac arrest, convulsions, coma and death.
Swallowing: Can cause nausea and can enter the bloodstream causing the same effects as listed under “skin”.
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 IMMEDIATELY and discard. Wash body with soap and water for at least 15 minutes.
Swallowing: Do NOT induce vomiting. Seek medical advice immediately.
Spill or Leak Procedures
Provide maximum ventilation. Eliminate ignition sources. 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 containers. Flush area with water, but prevent it from entering waterways. 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 full protective clothing and self-contained breathing apparatus. Use foam, dry chemical or carbon dioxide to put out fires. Cool fire exposed containers with water spray.
Storage and Handling Procedures
Store in properly closed, labelled containers. Keep away from acids, organic peroxides, oxidizing agents, and aldehydes in acidic medium. Store in a cool, well ventilated area, 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.