Statutory Inspections · Mandatory · Pre-Construction

COSHH Assessment — Epoxy Resins

A COSHH assessment for epoxy resin products used in structural repair mortars, flooring systems, adhesives, grouts, waterproofing, and protective coatings. Epoxy resins are skin sensitisers causing occupational contact dermatitis; amine hardeners are respiratory sensitisers. Nitrile gloves (minimum 0.4mm) required; skin health surveillance mandatory. Sensitisation is irreversible.

Last reviewed: 2 April 2026 — This guide reflects UK law as of this date. COSHH Regulations 2002 remains current with no amendments enacted as of 2 April 2026. Next scheduled review: 2 April 2027.

Document type	T7 — COSHH Assessment: Epoxy Resins
Primary legislation	COSHH Regulations 2002, EH40 Workplace Exposure Limits
Where used	Structural repair, flooring systems, adhesives, grouts, waterproofing membranes, protective coatings, crack injection, bonding agents
Resin component	Skin sensitiser — causes allergic contact dermatitis. Once sensitised, any skin contact with uncured epoxy triggers severe dermatitis
Hardener component	Amine-based hardeners are respiratory sensitisers — can cause occupational asthma. Also cause severe skin and eye burns
Glove requirement	Nitrile gloves minimum 0.4 mm thickness. Latex gloves do NOT provide adequate protection against epoxy resins
Health surveillance	Skin health surveillance required for all workers regularly handling epoxy products

1. Why Epoxy Resins Require a Dedicated COSHH Assessment

Epoxy resin systems are two-component products consisting of a resin (typically bisphenol A diglycidyl ether, DGEBA) and a hardener (typically an amine or polyamide). They are used extensively in construction for structural repairs, floor coatings, adhesive bonding, waterproofing, grouting, crack injection, and protective coatings. When the resin and hardener are mixed, a chemical reaction (curing) occurs that produces a hard, durable, chemically resistant material. It is during the mixing, application, and curing stages — when the components are in their uncured liquid or paste state — that the health hazards are most acute.

The resin component is a potent skin sensitiser. Repeated or prolonged skin contact with uncured epoxy resin causes allergic contact dermatitis in a significant proportion of exposed workers. Studies consistently report sensitisation rates of 2–10% among workers who regularly handle epoxy products, making it one of the most common causes of occupational skin disease in the construction industry. Once a worker is sensitised, even minimal skin contact with uncured epoxy — a splash, a smear on the wrist, resin on a tool handle — triggers a severe dermatitis reaction. Sensitisation is permanent and irreversible.

The hardener component presents a different but equally serious hazard. Amine-based hardeners are respiratory sensitisers and can cause occupational asthma. They are also corrosive, causing severe chemical burns to the skin and eyes on contact. When epoxy systems are applied in warm conditions or in poorly ventilated spaces, amine vapour is released that can irritate the respiratory tract and, with repeated exposure, cause sensitisation. The combination of a skin-sensitising resin and a respiratory-sensitising hardener makes epoxy systems a dual-hazard product that requires careful, documented controls.

Nitrile gloves minimum 0.4 mm — latex is not adequate

Latex gloves do not provide an effective barrier against epoxy resin components. Uncured epoxy resin permeates through latex within minutes, allowing skin contact and accelerating sensitisation. Nitrile gloves with a minimum thickness of 0.4 mm are the standard for epoxy work. Thinner nitrile gloves (such as the 0.1 mm examination gloves commonly found on construction sites) are also inadequate — they tear easily and do not provide sufficient chemical resistance. Gloves must be changed regularly during extended tasks, as permeation increases over time even through adequate gloves. Check the glove manufacturer's breakthrough time data for the specific epoxy product being used.

2. Key Content of the COSHH Assessment

The COSHH assessment for epoxy resins must address the specific hazards of both the resin and hardener components, the tasks during which exposure occurs, and the controls required to prevent skin sensitisation, respiratory sensitisation, and chemical burns. The following table sets out the key content areas.

Section	Content required
Product(s) assessed	Full product name for both resin and hardener components. Manufacturer, SDS reference numbers, chemical identifiers (CAS numbers for key hazardous components). Mixing ratio and pot life.
Task description	Specific task: mixing, applying by trowel/roller/brush, injection, pouring, grinding cured epoxy. Duration, frequency, area of application, whether indoor or outdoor, ventilation conditions.
Persons exposed	Operatives mixing and applying the product, labourers assisting, other workers in the area. Number of persons and duration of potential exposure for each group.
Hazardous components	Resin: bisphenol A diglycidyl ether (DGEBA) — skin sensitiser, skin and eye irritant. Hardener: amine type (aliphatic, cycloaliphatic, or aromatic) — respiratory sensitiser, corrosive to skin and eyes. Reactive diluents: may increase skin penetration and sensitisation risk.
Exposure routes	Skin contact (primary route for resin sensitisation). Inhalation of amine vapour (primary route for respiratory sensitisation, especially in warm or enclosed conditions). Eye contact (corrosive hardener). Ingestion (hand-to-mouth transfer if hygiene is poor).
Controls — Skin	Nitrile gloves minimum 0.4 mm thickness, changed regularly. Full-length sleeves. Safety goggles or face shield when pouring or mixing. Disposable overalls for large-area applications. Immediate washing with soap and water if skin contamination occurs. Never use solvents to clean epoxy from skin.
Controls — Respiratory	Adequate ventilation for all indoor applications. Forced-air ventilation or LEV for confined or poorly ventilated areas. Half-mask with A2 organic vapour filter for tasks generating amine vapour in enclosed spaces. Air monitoring where respiratory exposure is uncertain.
Controls — Working practice	Mix only the quantity needed (minimise waste and exposure time). Use tools with long handles to increase distance from the product. Cover open containers when not in use. Clean tools immediately after use. Segregate uncured epoxy waste for appropriate disposal.
Skin health surveillance	Baseline skin assessment before first exposure. Regular skin checks (minimum every 3 months for regular users) by a trained responsible person. Referral to occupational health if any signs of dermatitis. Records retained for 40 years.
Training	All workers must receive specific training on: the health hazards of uncured epoxy (sensitisation is permanent), correct glove selection and use, skin decontamination procedures, symptom reporting, and the importance of never allowing skin contact even for 'brief' tasks.
Emergency procedures	Skin contact: remove contaminated clothing, wash with soap and water (never solvents). Eye contact: irrigate for minimum 15 minutes, seek medical attention. Inhalation: move to fresh air, seek medical attention if symptoms persist. Spill: contain with inert absorbent, dispose as hazardous waste.
Assessor	Name, qualifications, and competence of the person who carried out the assessment. Date of assessment and review date.

Never use solvents to clean epoxy from skin

A common and dangerous practice on construction sites is to use acetone, white spirit, or other solvents to clean uncured epoxy resin from hands and forearms. Solvents dissolve the skin's natural protective barrier, dramatically increasing the rate of epoxy absorption into the skin and accelerating the sensitisation process. A worker who uses solvent to clean epoxy from their skin is far more likely to become sensitised than one who washes with soap and water. The correct procedure is always soap and water — never solvents.

3. Common Mistakes

Using latex gloves instead of nitrile for epoxy handling

Latex gloves do not provide a reliable chemical barrier against epoxy resin components. Uncured epoxy permeates through latex rapidly, allowing sustained skin contact that the wearer may not be aware of. This is one of the most common causes of epoxy sensitisation on construction sites. Workers assume they are protected because they are wearing gloves, when in reality the gloves are providing little or no protection. Nitrile gloves with a minimum thickness of 0.4 mm are the required standard. Gloves must be inspected before use for tears or pinholes, and changed regularly during extended tasks as permeation increases over time.

Not protecting skin for brief contact tasks

A persistent and dangerous misconception is that skin protection is only necessary for prolonged epoxy handling, and that brief tasks — trowelling a small repair, touching up a coating edge, wiping a drip — do not require full glove and skin protection measures. This is wrong. Sensitisation is a cumulative process driven by the total number of skin exposure events, not the duration of each individual event. Multiple brief, unprotected contacts with uncured epoxy are at least as dangerous as a single prolonged contact. Every contact with uncured epoxy must be a gloved contact, regardless of how short the task.

4. Related Documents

Document	Relationship
C1 — COSHH Assessment: General Site Substances	The general site COSHH assessment provides the overarching framework. Epoxy resins require a dedicated assessment because of their specific sensitisation hazards, glove specification requirements, and skin surveillance needs.
C6 — COSHH Assessment: Adhesives and Resins	The general adhesives and resins COSHH assessment may cover epoxy products at a high level. This dedicated epoxy assessment provides the detailed controls, glove specifications, and skin surveillance requirements that the general assessment cannot adequately address.
T6 — COSHH Assessment: Isocyanates	Isocyanates are another class of construction sensitisers. Where both epoxy and isocyanate products are used on the same project, both COSHH assessments apply. Workers may be exposed to multiple sensitisers simultaneously, compounding the risk.
T8 — Skin Health Surveillance Record	The skin health surveillance record documents the periodic skin checks required for epoxy-exposed workers. This is a direct output of the epoxy COSHH assessment requirement for skin health surveillance.

5. Frequently Asked Questions

Can epoxy cause occupational asthma?▾

Yes. The amine-based hardeners used in epoxy resin systems are respiratory sensitisers and can cause occupational asthma with repeated inhalation exposure. This is most likely to occur when epoxy products are applied in warm conditions (which increases amine vapour release) or in poorly ventilated or confined spaces. Once respiratory sensitisation has occurred, it is permanent, and even low-level amine exposure can trigger asthma attacks. Adequate ventilation is essential for all indoor epoxy applications, and respiratory protective equipment must be specified for enclosed or poorly ventilated areas.

Is cured (hardened) epoxy still hazardous?▾

Fully cured epoxy resin is generally considered non-hazardous in its solid form. The hazardous components have reacted and are no longer available for skin or respiratory exposure. However, grinding, cutting, or sanding cured epoxy generates dust that can irritate the respiratory tract and skin, and some partially cured or under-mixed areas may still contain unreacted components. Dust from grinding cured epoxy should be controlled with LEV or wet methods, and appropriate RPE should be worn.

How often should gloves be changed when working with epoxy?▾

Gloves should be changed immediately if they are torn, punctured, or visibly contaminated on the inside. For continuous work, gloves should be changed at least every 30 to 60 minutes, depending on the breakthrough time stated in the glove manufacturer's data for the specific epoxy product. Even nitrile gloves with adequate thickness will eventually allow permeation of epoxy components — changing them regularly is the only way to maintain the protective barrier. Always wash hands before putting on new gloves.

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