EN ISO 374 Type A, B and C gloves explained

Under the classification used in EN ISO 374-1:2016+A1:2018, the glove type depends on how many listed test chemicals reach a qualifying permeation performance level. The type describes breadth within that defined laboratory test, not protection against all chemicals.

• Type A - performance level 2 or higher, meaning a measured breakthrough time greater than 30 minutes, for at least six listed test chemicals.
• Type B - performance level 2 or higher for at least three listed test chemicals.
• Type C - performance level 1 or higher, meaning a measured breakthrough time greater than 10 minutes, for at least one listed test chemical.
• A Type C glove may have strong data for one relevant chemical, while a Type A glove may still be unsuitable for the particular chemical, mixture, concentration, temperature or contact pattern in your task.

ISO published ISO 374-1:2024 in July 2024 and lists ISO 374-1:2016 and its 2018 amendment as withdrawn at international level. That does not mean every EN adoption, designated or harmonised standard reference, certificate and product document changed on the same date.

For a UK or European purchase, record the exact standard and edition shown on the declaration, certificate, report, marking and instructions. Then verify whether that reference is appropriate for the destination market and conformity route. Do not silently replace the edition on a supplier document with the newest ISO publication date.

For Type A and Type B markings under the 2016+A1:2018 classification, code letters identify the listed chemicals that achieved the qualifying result. Concentration is part of the identity, so a letter without its test context is incomplete.

• A methanol; B acetone; C acetonitrile; D dichloromethane; E carbon disulphide; F toluene.
• G diethylamine; H tetrahydrofuran; I ethyl acetate; J n-heptane; K sodium hydroxide 40%; L sulphuric acid 96%.
• M nitric acid 65%; N acetic acid 99%; O ammonium hydroxide 25%; P hydrogen peroxide 30%; S hydrofluoric acid 40%; T formaldehyde 37%.
• The absence of Q and R is intentional in this code sequence. Do not invent a chemical for a missing letter or assume an unlisted workplace mixture is covered by similarity.

Permeation is molecular movement through the glove material. The classification uses measured breakthrough time from controlled laboratory testing, commonly reported as levels 1 to 6.

• Level 1: greater than 10 minutes; level 2: greater than 30 minutes.
• Level 3: greater than 60 minutes; level 4: greater than 120 minutes.
• Level 5: greater than 240 minutes; level 6: greater than 480 minutes.
• A laboratory breakthrough time is not an automatic workplace wear time. Temperature, stretching, abrasion, movement, prior contact and mixtures can reduce real-world protection.

These three terms answer different questions and should not be merged into a single claim. HSE guidance also warns that no glove material protects against every substance or forever.

• Permeation - movement of a chemical through the material at molecular level, without relying on a visible hole.
• Penetration - bulk flow through imperfections such as pinholes, seams or other discontinuities, assessed separately under EN ISO 374-2.
• Degradation - a damaging change in a physical property after chemical contact, assessed under EN ISO 374-4 and reported for the tested chemical.
• A permeation result does not cancel an adverse degradation result, and passing penetration testing does not establish a useful permeation time for a named chemical.

NewGlove's February 2026 NewEvo+300 data sheet identifies product references NE3S-XBC, NE3S-XBS and NE3S-XW and states EN ISO 374-1:2016+A1:2018 Type C. Its table reports permeation levels for 40% sodium hydroxide, 30% hydrogen peroxide and 37% formaldehyde, with separate degradation results.

That table is more informative than the Type C label alone. It also states that chemical resistance was assessed under laboratory conditions on samples from the palm and relates only to the chemical tested. A buyer should match the current report and declaration to the exact reference, size or colour scope where applicable, intended use and destination market before relying on it.

Begin with the task, not the glove type. Shortlist only after the hazard and contact pattern have been described in writing.

• List every substance and mixture, its concentration, temperature and physical form; obtain the current safety data sheet.
• Define splash, intermittent contact or immersion, expected contact duration, movement, abrasion and the area of the glove exposed.
• Request the current declaration, certificate, instructions and full permeation, penetration and degradation evidence for the exact glove.
• Check the standard edition, test method, laboratory, product references, specimen location and any conditioning or test limitations.
• Compare the result for the actual chemical and concentration. Do not substitute a material chart or a different glove from the same range.
• Set use, inspection, change and disposal rules through the workplace risk assessment, then train users and review performance.

A concise evidence request is usually more useful than asking whether a glove is simply chemical resistant.

• Which exact product references and sizes does the report cover?
• Which standard edition and test method were used, and is that reference appropriate for our destination market?
• Which chemical, concentration and permeation level support each code letter or claim?
• What degradation result was recorded for each claimed chemical?
• Were samples taken from the palm only, and what does the instruction document say about mixtures and workplace conditions?
• Has the formulation, thickness, factory, report or certification scope changed since the evidence was issued?