The protection professionals explain: Anyone who works with chemicals, viruses or bacteria needs reliable protective gloves. The international standard EN ISO 374 regulates exactly how these gloves are tested and classified – so you can make an informed decision about which glove is right for your work.
What does the EN ISO 374 standard regulate?
EN ISO 374 is a multi-part standard. It describes how protective gloves must be tested to protect against dangerous Chemicals and Microorganisms such as bacteria, fungi or viruses. Depending on their resistance to certain fabrics, the gloves are made in three types of protection scaled:
- Type A: Protection against at least 6 chemicals (breakthrough time ≥ 30 minutes)
- Type B: Protection against at least 3 chemicals (breakthrough time ≥ 30 minutes)
- Type C: Protection against 1 chemical (breakthrough time ≥ 10 minutes)
💡 Breakthrough time (permeation) indicates how long it takes for a chemical to diffuse through the glove material.
Other requirements of the standard – briefly explained
- EN 374-2: Test the Penetration – i.e. whether liquids or microorganisms penetrate through visible pores or material defects.
- EN 374-4: Evaluates the Degradation – whether the material softens due to chemicals, becomes brittle or fails mechanically.
- EN ISO 374-5: Regulates the Protection against microorganisms.
🔎 Gloves with protection against bacteria and fungi bear a corresponding symbol. In the case of extended protection against viruses, the word "VIRUS" is written under the pictogram.
You should know these pictograms
- Chemical protection: Erlenmeyer flasks, supplemented by protection type (A, B, C) and the letters of the tested chemicals
- Microbiological protection: Microorganism symbol (bacteria & fungi), in the case of virus protection also with "VIRUS"
The symbols show you at a glance which dangers a glove has been tested against - for more safety without technical jargon.
What chemicals are tested?
The EN ISO 374 standard lists 18 defined test chemicals, each of which is assigned to a letter. Here is the complete list:
| Letter | Chemical | CAS No. |
| A | Methanol | 67-56-1 |
| B | Acetone | 67-64-1 |
| C | Acetonitrile | 75-05-8 |
| D | Dichloromethane | 75-09-2 |
| E | Carbon disulfide | 75-15-0 |
| F | Toluene | 108-88-3 |
| G | Diethylamine | 109-89-7 |
| H | Tetrahydrofuran | 109-99-9 |
| I | Acetic Acid Ethyl Ester | 141-78-6 |
| J | n-heptane | 142-82-5 |
| K | Sodium Hydroxide 40% | 1310-73-2 |
| L | Sulfuric acid 96 % | 7664-93-9 |
| M | Nitric acid 65 % | 7697-37-2 |
| N | Acetic acid 99 % | 64-19-7 |
| O | Ammonium Hydroxide 25% | 1336-21-6 |
| P | Hydrogen Peroxide 30% | 7722-84-1 |
| S | Fluoric acid 40 % | 7664-39-3 |
| T | Formaldehyde 37% | N.A. |
The CAS number is an internationally unique identification number for chemical substances.
Important: Many manufacturers also test their gloves for other chemicals. These do not appear in this list of standards, but in the manufacturer's specifications. If in doubt, ask your supplier.
Why all this is important
The EN ISO 374 standard ensures safety through traceability. Clearly defined test procedures and uniform symbols help you to find the right glove for your specific area of application. But standards alone are not enough: The decisive factor is how you use the glove in practice.
Whether in the laboratory, industry or healthcare - you should always make sure that the glove fits the respective chemical, the contact time and the wearing conditions.
Tip: Find out about the manufacturer's specifications, take advantage of consulting services and train your team. This way you can play it safe.