If you are smarter than I was when I first used epoxy, you are asking this question prior to pouring. When I first poured epoxy, I was unaware of the scent, fumes, and dangers that it could have – particularly when using cheaper brands.
All epoxy resin has some odor to it, however many brands are able to minimize this to be almost negligible. Deep pouring epoxies, along with more naturally derived epoxy, tend to have less scents associated with them during the pouring and curing process.
While it may be disheartening to learn that there will be some scent associated with pouring epoxy, it is important to remember that smell alone is not all that should be taken into consideration when pouring indoors or without a mask.
Why Does Epoxy Resin Smell Bad?
While it is easy for me to sit here and tell you that epoxy resin has an odor, it is more important to understand why this is. There is one primary reason that epoxy resin has a pungent odor to it.
In common applications, a base epoxy is mixed with a curing agent. When these two are mixed, there is an exothermic reaction. This chemical reaction and heat is what releases the odor as the epoxy hardens. As the epoxy hardens, the gas released will subside and eventually disappear.
Knowing why this happens is important because it can help avoid worse odors (particularly if you are pouring indoors). Using the logic of exothermic reactions and gas being released during this, it is easy to understand why deep pouring epoxy resins tend to have less odor associated with them.
Deep pour resins are made possible by having a lower viscosity, and staying cooler during the curing process. Because the chemical reaction is not as hot, they are able to have deeper epoxy without the dreadful effects of overheating. Because they stay cooler, there is less odor released during the curing process. Similar ideas can be said of more natural epoxy resin and those that are engineered to have less odor. They are created in a way that emits less gas during the curing process.
How Long Does the Epoxy Resin Smell Last?
Having poured epoxy resin for many years, I can tell you that one of the most concerning feelings is when the odor does not seem to dissipate as quickly as it has been advertised. This was my fear early on and is a common question I run into.
Epoxy resin can leave a bad odor in the air for anywhere from 24 hours to a week. This time can be lengthened if you are not properly ventilating the area or you had a pour that did not cure. The odor should be gone shortly after a full cure, which can vary based on the type of epoxy, temperature, humidity, and materials used, but the scent will always go away as long as the epoxy cures.
In general, if you are using a standard epoxy resin and working in a well-ventilated area, you can expect the odor from the epoxy resin to be gone in 48-72 hours. There may be some lingering scent beyond this, but it will be very minimal and unlikely to be noticed.
How to Minimize Epoxy Resin Odors
Now that you have an understanding of why epoxy resin releases odors, you are probably curious as to how to reduce the fumes of epoxy resin. Unfortunately, there are no perfect solutions to this. There are different ways you can expedite the odor, or to minimize the odor overall strength, but they are far from foolproof.
- Using an epoxy that is low-odor. Some epoxy resin companies will claim an odorless scent. While we may attain that one day, I have not found one that is fully odorless. Usually these are more natural, and deeper pouring epoxies.
- Keeping the room and surface cold. This will help keep the odor from the epoxy resin less potent. This will, however, increase the length of time that the epoxy resin releases an odor. This is a double-edged sword.
- Heating the epoxy resin. Since the chemical reaction that causes epoxy to cure is exothermic (i.e. releases heat), you can expedite the process by ensuring the epoxy stays at a hot (but safe) temperature.
Are Epoxy Resin Fumes Harmful?
While epoxy resin can have a putrid odor emitted, this is not indicative of whether or not this is harmful to the user. This is the most important question and guideline you should understand when working with epoxy resin.
Just because an epoxy resin does not have an odor does not mean that it is safe, and vice versa. The epoxy resin odor has little to do with harmful chemicals or fumes, and has more to do with the chemical reaction in the curing. You could have a terribly strong-smelling epoxy that is perfectly safe to inhale.
In general, most epoxy resins today do not emit fumes that are considered harmful. This is measured using volatile organic compounds (VOC’s), which can be anything that has high vapor pressure at room temperature. Most reputable epoxy resins do not contain any VOC’s.
What is a VOC in Epoxy Resin?
As mentioned above, VOC’s can be any volatile organic compound. When it comes to epoxy resins, this means that VOC’s are fillers, dillutants, or other unnecessary additional components in the epoxy resin that allow the manufacturer to sell it at a lower cost.
This is an important reason not to shop for the cheapest epoxy. If you are finding the cheapest epoxy, chances are you are going to end up with something that has fillers and is potentially harmful to your health if you are not taking extreme safety precautions.
Epoxy resin is a great tool that can be used for industrial purposes and art alike. While there will be some level of smell that is emitted from using epoxy resin, and you can minimize that with the right brand, the most important thing to find out is whether or not the epoxy is emitting dangerous fumes with VOC’s.