Hi Joe,

I have a product that is used in the garden/composting space, and some of my customers are extremely finicky, so trying to understand if there are any residual TGIC issues. Is TGIC still actively toxic once the polyester powder cure has been oven cured? Is there residual TGIC in the cured coating? Is residual TGIC capable of migration to the surface and into another substance the powder coat is in contact with, like soil/compost?

We are also asking the same of our powder coating supplier but am asking an independent position due to your position within the industry.

Kind Regards,

Owen Luke

Wollongong Area 

Australia

Hey Owen,

Thanks for your questions. They are reasonable ones for someone handling a potential for a known toxic chemical leaching into plants, vegetables and possibly the water table. TGIC (triglycidyl isocyanurate) has been meticulously studied and analyzed since the late 1980s. The main concerns had to do with handling the neat material and also a formulated powder coating. Studies showed that TGIC is a potential mutagen in laboratory animals. This is reason enough to require hazard labeling on both the raw material and products containing it.

Whether residual TGIC remains after a coating has been cured is a good question. Studies commissioned by Nissan Chemical suggest that if there is, the levels are undetectable. So, the possibility of TGIC leaching out of a cured film is extremely remote. That being said, one could argue "how can you prove that a coating has been fully cured?" And this is a good point. My personal opinion is that there is no hazard of leaching if you are convinced that the coating was fully cured. How to prove that is another question.

The safest path forward is to coat compost/garden items with non-TGIC powder coatings. Practically speaking however, the risk is extremely minute.

Please let me know if you have any more questions.

Kind regards,

Joe Powder

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