Working safely with epoxy: skin, eyes and air

This page summarizes what occupational-health agencies and resin manufacturers publish about working with epoxy. It is general information for planning a project. It is not medical advice, and it does not replace the safety data sheet (SDS) for the product you use. If you have been exposed or have symptoms, follow the first-aid section of the SDS and contact a medical professional or poison center.

The main hazard: skin sensitization

EU-OSHA describes epoxy products as potent skin sensitizers, and says skin contact with the separate components or the mixed product frequently leads to allergic contact dermatitis, usually on the hands and forearms and sometimes the face (EU-OSHA). The same page explains why this matters long term: someone who has developed an epoxy allergy reacts more strongly after each contact, and avoiding all contact becomes the only option.

The practical rule is that no uncured resin or hardener should touch your skin, ever, not only that you should wash it off quickly.

NIOSH makes the same distinction between states: before they cure, some epoxy and resin components can be hazardous, while cured epoxies are usually safer to handle than their uncured components (NIOSH).

What the safety data sheets say

Every product’s SDS lists its own hazard statements. A few examples from our database:

• EcoPoxy FlowCast: Part A lists skin and eye irritation (H315, H319), may cause an allergic skin reaction (H317) and suspected of causing genetic defects (H341); Part B lists causes severe skin burns and eye damage (H314), causes serious eye damage (H318), and harmful if swallowed or in contact with skin (H302, H312) (Part A SDS, Part B SDS).
• Smooth-On EpoxAcast 692: Part A lists skin and eye irritation (H315, H319) and may cause an allergic skin reaction (H317); Part B causes serious eye damage (H318), is harmful if swallowed or in contact with skin (H302, H312) and is toxic to aquatic life with long-lasting effects (H411) (SDS).

In both examples the hardener (Part B) carries the more serious eye warning. Allergy warnings can appear on either part: ArtResin’s hardener SDS, for instance, also lists H317 (ArtResin hardener SDS). Read both. Each product page in our database summarizes the SDS hazard statements with a link to the full document.

Protective equipment

Gloves. EU-OSHA recommends protective gloves made of nitrile or butyl rubber, changed at the end of each shift and immediately if the inside becomes contaminated (EU-OSHA). NIOSH adds that gloves have to be the right material or they may not protect you (NIOSH). Check the glove materials in section 8 of your product’s SDS; Smooth-On’s SDS for EpoxAcast 692, for example, names butyl rubber, neoprene or PVC (SDS).

Eyes. EU-OSHA recommends safety goggles, and a face shield when splashes may occur (EU-OSHA). EcoPoxy warns that eye exposure to hardeners can cause severe, permanent damage (EcoPoxy).

Clothing. EcoPoxy says to wear clothing that protects the whole body from splashes (EcoPoxy). NIOSH advises changing clothes as soon as possible if chemicals get on them, and avoiding carrying contamination home on work clothes or shoes (NIOSH).

Air and ventilation

NIOSH advises increasing ventilation as much as possible and warns that smell is not a reliable guide to whether you are safe (NIOSH). EU-OSHA recommends respiratory protection when solvent-based epoxy products are used and whenever any epoxy is sprayed (EU-OSHA).

Manufacturers’ requirements for pouring (not spraying) vary by product. EcoPoxy, for example, says its resins can be used in a well-ventilated indoor space without respiratory protection, excluding spray applications (EcoPoxy). Other SDSs call for a respirator where ventilation is not enough; ArtResin’s, for example, specifies an organic-chemical cartridge respirator when working in a non-ventilated area (ArtResin resin SDS). Follow section 8 of your product’s SDS.

A separate air hazard comes from overheating. West System warns that epoxy curing out of control becomes hot and frothy and releases toxic vapors (West System); see why deep pours overheat.

A simple routine

1. Download the SDS for both parts before buying or opening them, and read sections 2 (hazards), 4 (first aid) and 8 (protective equipment).
2. Set up ventilation before you open the containers.
3. Put on gloves of the material the SDS names, eye protection, and long sleeves.
4. Keep uncured resin off your skin. Change gloves when they are contaminated.
5. Wash hands with soap and water before eating or drinking, as EcoPoxy advises (EcoPoxy).
6. Set leftover mixed resin aside to cure where you can monitor it, as West System advises (West System).

Children and pets

EcoPoxy does not recommend that young children use epoxy products, because they may not avoid eye or skin exposure and may lack properly fitting protective equipment (EcoPoxy). Keep uncured materials, mixing cups and wipes out of reach.