Resin in this context refers to epoxy resin that you use in order to put together broken items. For example, you might end up putting ceramic back together with epoxy resin glue. There’s also epoxy cookware that you might want to research
So is resin microwave safe? Keep on reading to find out. Some epoxy resin cookware is safe for quick microwaving, but for the most part, don’t bother microwaving it and just use the tried-and-true ceramic dishes.
Is Resin Microwave-Safe?
First off, is epoxy cookware safe for microwaving in light of its resin content? If epoxy resin is microwave-safe then it should be safe, right? The thing is that properly cured epoxy resin is considered microwave-safe. Tests done to it alone yields that it doesn’t heat up when exposed to microwave rays.
However, while the epoxy itself is safe for microwaving you can’t say the same for what it’s putting together as glue. Even if it’s broken ceramic, which is known for its microwaveable properties, you shouldn’t microwave it along with epoxy despite both being microwave-safe.
This is because even though neither heats up when microwaved, the epoxy resin glue used might not be well-cured and anything already cracked, even when glued back together, shouldn’t be put inside the microwave oven due to the risk of thermal shock or recracking.
Further reading: What Can You Put in a Microwave?
What is Epoxy Resin Anyway?
Epoxy refers to the colloquial or layman’s term for the epoxide functional group. It also refers to any of the base components or the cured end products of epoxy resins. Epoxy resins can either be material used for constructing things like epoxy cookware or bonding adhesive material (like superglue).
Epoxy resins—which are also known as polyexposides “scientifically”—belong to a class of reactive prepolymers and polymers. They contain epoxide groups for good measure. In regards to whether or not epoxy resin is plastic, yes. Yes, it is a type of plastic.
Therefore, on top of worries regarding whether resin would melt in your microwave, you might have additional concerns regarding resin producing toxic chemicals when heated by microwave rays, such as plasticizers like BPA.
The Material Bonded to the Epoxy Resin
The material bonded by epoxy might have a different reaction to the microwave when exposed to microwave radiation. Even if the material itself is microwave-safe cracked bowls or dishes bonded by epoxy resin might become unglued when push comes to shove.
Furthermore, the epoxy you’ve used to fix a shattered bowl or mug might not be well-cured, with the microwave heat exposing the fact. Therefore, it’s not recommended that you microwave anything you’ve made or fixed using epoxy resin.
Always Err on the Side of Caution
In the end, it’s best to err on the side of caution. Even though epoxy resin has microwave-safe properties, you don’t want to risk BPA or plasticizer contamination on your food. It’s especially true of cookware lacking the microwave-safe labeling.
This goes double for materials put together using resin glue. Consult professionals directly to be sure, but most of them will say to just reheat or cook your food using microwave-safe ceramics anyway.
How Do Microwave Ovens Work?
Microwaves heat food by making the water molecules inside them move so fast that their temperature is raised. The miniature rays or micro radiowaves from the microwave’s magnetron excite the water particles as well as fat molecules of the food.
This results in insanely quick heating that’s much faster to do than conductive heating from stovetops or preheated conventional ovens. The quick molecule movement that’s induced by microwaves causes food or beverages to get quite hot.
Heating water to boiling on your stovetop roughly takes 5 to 10 minutes to do. In contrast, you can make a mug of water go near-boiling within a minute of microwaving. That’s how fast microwaves are at heating up anything.
Is Cured Epoxy Microwaveable?
What happens when a piece of cured epoxy is microwaved? After epoxy is cured into epoxy resin, it turns into a plastic polymer that resembles glass. According to certain scientific papers covering microwave absorption by epoxy resin, the resin absorbs microwaves but not the kind found in ovens.
While it is possible for epoxy—specifically BaTio3/Epoxy and NiFe2O4/Epoxy composites—to absorb certain types of micro radiowaves, it’s of a different wavelength compared to microwaves emitted by consumer-grade microwave ovens.
In other words, epoxy resin glue or adhesive shouldn’t heat up inside household microwave ovens because the only type of microwaves that could heat it up are much higher in wavelength compared to those emitted by your microwave oven.
What Does Microwave-Safe Mean?
There’s no standardized definition of what microwave-safe is. It’s not enough that the container doesn’t heat up. It also shouldn’t leach off toxic chemicals, as in the case of microwave-safe and BPA-free plastic containers.
Microwave-safe means containers and dishes that don’t react negatively to both the microwave rays and the hot food they’ve microwaaved (they remain cool to the touch afterwards). They should have insulator properties at absorbing conductive heat while letting microwave rays pass themselves.
Epoxy resin is technically microwave-safe due to microwave oven wavelengths not matching the wavelength needed to heat it up. However, since it’s plastic, there’s another concern regarding heating it up in the microwave—how toxic or non-toxic it becomes when microwaved.
Even if a plastic container could survive microwaving without heating up at all, the heat could have it leaching off plasticizers like BPA unto your food, thus contaminating it. Ceramic plates bonded by epoxy resin adhesive might not be safely microwaved no matter how good the resin has cured.
Conclusion
In practice, microwave-safe means containers that don’t break or melt under microwave ray heat as well as don’t leach off chemicals unto your microwaved food.
Even though properly cured epoxy resin itself is microwave-safe, it doesn’t mean that the material bonded to the epoxy (in the case of epoxy resin glue or epoxy cookware) is also microwave-safe. You can only use epoxy resin containers and whatnot if everything is microwave-safe.
If it contains metal or if it’s bonding together broken ceramic, you might be in trouble. The epoxy might unbond or unglue itself if used as glue on ceramic and, besides which, broken or cracked anything shouldn’t be microwaved in the first place.
References:
- “Does epoxy resin resist the oven’s micro-waves?“, Quora.com, January 22, 2016
- Antony Njoroge, “Is Epoxy Resin Microwave Safe?“, WorkBenchPlanet.com, Retrieved May 23, 2021
