Health risks: polyester versus epoxy

[David Fisher]

Hi All. There is often discuusion about the various safety concerns for both polyester and epoxy resins. I have used both a fair bit, both in repairs and building from scratch, and particularly as a kid didn't pay any attention to safety. Poly, with it's noctious fumes and heat reaction, seems superficially to be more dangerous, however I do hear stories about the danger of epoxy.

Can anyone answer definitively what the dangers of both are to one's long term health?

David.

[jimslade]

Styrene kills brain cells. Both have liver problems with long term exposure and brain cancer. Always have good ventilation to reduce the risks. In my experiance in the autobody business the most damage done is self inflicted,ie smoking and drinking. In my shop you will not smell anything. My ventilation fans run continually. It costs more, but put a price on your health, whats it worth?

[JEM]

Most epoxies have amines. This is what causes problems with those folks who have problems with epoxy. Some of the newer epoxies and/or most slow-cure epoxies have little or no amines.

I've used cheaper epoxy (typically the ones with like 3:1 or 4:1 mix ratio) and you can tell the difference with regard to the smell as compared to like System Three or RAKA 2:1 mix ratios.

[Herman]

Basicly your right. The 2:1 systems or anything in that area are usually mannich base hardeners, which contains mostly bonded amine, which is less likely to harm you. This epoxy is very popular in the flooring business, where large amounts of epoxy are spread out onto the floor. You do not want anything smelly over there. Just recently we got some products changed, to comply with a "below 3 ppm" regulation for fumes. 3 ppm is very, very low.

On the other hand, if you need stronger epoxy, with higher heat resistance, you turn to IPD based hardeners, which have more amine groups, and therefore are more smelly. They usuallly also need extra heat to cure thoroughly (postcure). Mixing ratios can be anywhere from 100:15 to 100:35

We have a lot of customers who use the IPD variants for infusion of hull, deck, stringers and bulkheads (where resin contact is unlikely), and glue the smaller stuff (interior, etc) with a mannich base.

Also on the polyester side, there is a trend of putting less and less styrene in. When I started selling the stuff, 50% was normal, and 40% was considered low. Now 32% is low, and 40% is normal. And this is not the end. I predict that within 3-4 years many polyesters will have less than 30% styrene content.

For both resin types the following is true:

There is no reason not to protect yourself.