Complete guide to chemical-resistant standard EN 374 for protective gloves

Key takeaways:

The EN 374 standard is a European benchmark that specifies the requirements for protective gloves against dangerous chemicals and micro-organisms.

EN ISO 374:2016 is structured into several parts, each focusing on a specific area of glove performance or requirement.

EN 374 classifies chemical protective gloves into Type A, Type B, and Type C based on their permeation resistance to a set of standard test chemicals.

Manufacturers must provide detailed user information with EN 374 certified gloves, including the manufacturer’s details, glove identification, and test results.

Selecting the right EN 374 glove involves considering the specific chemical hazards, exposure duration, and the need for dexterity.

What is the core function of the EN 374 standard?

The EN 374 standard acts as a key European benchmark, outlining how protective gloves should perform when shielding users from dangerous chemicals and micro-organisms. Essentially, it creates a unified system for testing, categorizing, and marking these gloves. This ensures people can confidently pick the right protection based on solid performance evidence. The standard covers how well gloves resist chemical permeation (seeping through at a molecular level), degradation (breaking down physically from chemical contact), and penetration (leaking through flaws like pinholes). It also addresses protection against bacteria, fungi, and sometimes viruses. The latest version, EN ISO 374:2016, includes updates to boost safety and make requirements clearer.

How is the EN ISO 374:2016 standard structured into parts?

The EN ISO 374:2016 standard is broken down into several specific parts. Each part zeroes in on a particular area of glove performance or requirement, allowing for precise specifications and testing methods for different kinds of resistance.

Defining EN 374-1: Requirements for chemical risks

EN 374-1:2016+A1:2018 lays out the terms and performance standards for gloves designed to protect against chemical hazards. It brings in the vital Type A, Type B, and Type C classification system. This system hinges on how well a glove resists permeation by chemicals from a set list of 18 test substances. This part dictates how many chemicals a glove needs to resist and the minimum breakthrough time for each classification, directly guiding glove choice based on the expected chemical danger level.

Assessing EN 374-2: Resistance to penetration

EN 374-2:2019 concentrates on figuring out a glove’s resistance to penetration. In this context, penetration means chemicals or micro-organisms getting through physical flaws like tiny holes, seams, or other defects in the glove material. This part requires specific checks, mainly air leak and water leak tests, to confirm the glove acts as a solid barrier against non-molecular level breaches. Passing these tests is essential for any glove claiming EN 374 protection against chemicals or micro-organisms.

Measuring EN 16523-1: Resistance to chemical permeation

EN 16523-1:2015+A1:2018, which took over from the older EN 374-3, explains the method for measuring how resistant a glove material is to liquid chemical permeation during continuous contact. Permeation is the molecular-level process where a chemical travels through the glove material itself. The main thing measured is the Breakthrough Time (BTT) – how long it takes for the chemical to get through. This test uses specific chemicals from the standard list, and the resulting BTT helps assign performance levels, which then determines the Type A, B, and C classifications.

Evaluating EN 374-4: Resistance to chemical degradation

EN 374-4:2019 deals with how well glove materials hold up against degradation from chemical contact. Degradation means negative changes to a glove’s physical state caused by chemical exposure, like swelling, shrinking, becoming harder or softer, or losing strength against punctures. This standard demands testing the change in puncture resistance after ongoing contact with a specific chemical. The outcome, shown as a percentage change, must be put in the user instructions, giving vital clues about how the glove’s physical structure might weaken during use.

Understanding EN 374-5: Protection against micro-organisms

EN 374-5:2016 sets out the terms and performance requirements for gloves protecting against micro-organisms, specifically bacteria and fungi. To claim this protection, a glove must first clear the penetration resistance test described in EN 374-2. If a glove also claims protection against viruses, it needs to pass an additional specific test based on the ISO 16604:2004 (Procedure B) standard. This test checks resistance to penetration by blood-borne pathogens using a bacteriophage challenge. Seeing the word “VIRUS” beneath the biohazard symbol signals this extra level of protection.

How does EN 374 classify chemical protective gloves?

EN 374 employs a tiered system, mainly relying on permeation resistance tests (EN 16523-1), to sort gloves based on the chemical protection level they provide. This classification makes it easier for users to pick gloves suitable for the particular chemical dangers and contact times they anticipate.

Explaining Type A, Type B, and Type C ratings

The EN 374-1 standard outlines three clear types of chemical protective gloves using their permeation performance against the list of 18 standard test chemicals:

• Type A gloves offer the highest resistance to chemical permeation. They need to reach at least performance level 2 (Breakthrough Time ≥ 30 minutes) against 6 or more of the 18 test chemicals,
• Type B gloves give moderate permeation resistance. They must hit at least performance level 2 (Breakthrough Time ≥ 30 minutes) against 3 or more of the 18 test chemicals,
• Type C gloves provide limited chemical permeation resistance. They have to achieve at least performance level 1 (Breakthrough Time ≥ 10 minutes) against just 1 of the 18 test chemicals.

This system clearly signals how suitable a glove is for various risk levels and exposure situations.

What do the permeation breakthrough time levels indicate?

The permeation Breakthrough Time (BTT), measured following EN 16523-1, is sorted into six performance levels. These levels show how long a glove material can hold off a specific test chemical under lab conditions before the chemical breaks through:

• Level 1: Breakthrough time ≥ 10 minutes,
• Level 2: Breakthrough time ≥ 30 minutes,
• Level 3: Breakthrough time ≥ 60 minutes,
• Level 4: Breakthrough time ≥ 120 minutes,
• Level 5: Breakthrough time ≥ 240 minutes,
• Level 6: Breakthrough time ≥ 480 minutes.

Knowing these levels is essential for assigning the Type A, B, or C classification, and they must be included in the user information for the specific chemicals tested.

Which specific chemicals are used in EN 374 testing?

The EN ISO 374:2016 standard requires testing against a defined list of 18 chemicals, up from the previous 12. This wider range allows for a more thorough evaluation of a glove’s chemical resistance. Each chemical gets a letter code that’s used on glove markings:

• 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 chemicals chosen represent various chemical families, like alcohols, ketones, acids, bases, and organic solvents.

How are EN 374 compliant gloves labeled and marked?

Clear, standard labels are vital so users can quickly tell what protection an EN 374 compliant glove offers. The markings show the type of protection and the specific substances the glove successfully passed tests against.

Decoding pictograms and chemical letter codes

Gloves meeting the standard show specific symbols. For chemical protection, the EN 374-1 symbol is a flask. Underneath this symbol:

• For Type A and Type B gloves, you’ll see the letter codes (A-T) for the chemicals where the minimum breakthrough time was met,
• For Type C gloves, only the flask symbol is shown, without letters, meaning it protects against at least one chemical for 10 minutes or more.

For protection against micro-organisms, the EN 374-5 biohazard symbol is used. This means the glove meets the penetration resistance rules for bacteria and fungi. If a glove has also passed the specific tests for virus protection according to ISO 16604:2004 Procedure B, the word “VIRUS” will be printed below the EN 374-5 biohazard symbol. If you don’t see “VIRUS”, the glove isn’t certified for virus protection under this standard, even if it has the basic biohazard symbol.

What information must manufacturers provide with EN 374 gloves?

Manufacturers have to give detailed user information with gloves certified to EN 374. This info is critical for choosing the right glove, using it correctly, and understanding its limits. Key required details include:

• The manufacturer’s name and address (or their authorized representative’s),
• Glove identification details (like product name or code),
• Size information,
• A reference to the specific EN ISO 374 parts the glove meets (e.g., EN 374-1:2016 Type A, EN 374-5:2016 VIRUS),
• The relevant symbols and, for Type A/B gloves, the letter codes of chemicals tested,
• The permeation performance levels achieved for the tested chemicals,
• The degradation test results (EN 374-4) for every claimed chemical, shown as a percentage change,
• A list of materials in the glove known to potentially cause allergies,
• Instructions covering storage, use, cleaning (if relevant), maintenance, and disposal,
• For gloves claiming micro-organism protection (EN 374-5), confirmation that protection levels don’t indicate duration and that penetration resistance was checked. If virus protection is claimed, specific mention of passing the ISO 16604 test is needed.

Providing this thorough information ensures transparency and helps users make informed risk assessments and manage their gloves properly.

What key updates were introduced in EN ISO 374:2016?

The EN ISO 374:2016 update brought several important changes from earlier versions, aiming for better clarity, broader testing scope, and improved user safety:

• Expanded Chemical List: the number of standard test chemicals grew from 12 to 18, offering a wider foundation for checking chemical resistance,
• Mandatory Degradation Testing: the EN 374-4 degradation test became required, and results must now be in the user instructions, giving insight into how chemical exposure affects the glove’s physical condition,
• New Classification System (Type A, B, C): introducing Type A, B, and C categories based on the number of chemicals resisted and breakthrough time created a clearer, tiered system for chemical protection levels,
• Revised Markings: symbols and related markings were updated for clarity, including specific indicators for Type A, B, and C gloves and the separate mark for virus protection under EN 374-5,
• Dedicated Micro-organism Standard (EN 374-5): a distinct part (EN 374-5) was created just for micro-organism protection, featuring clearer rules for virus protection testing,
• Permeation Testing Standard Update: EN 16523-1 officially replaced EN 374-3 as the go-to standard for chemical permeation testing.

Together, these updates make the standard for chemical and biological protective gloves more rigorous and informative.

How do you choose the appropriate EN 374 glove for a task?

Picking the right EN 374 glove involves carefully thinking about the specific dangers and what the job entails. A methodical approach helps ensure the best protection and usability.

Matching gloves to chemical hazards using SDS

First off, identify every chemical involved in the job. Check the Safety Data Sheets (SDS) for each one, paying close attention to Section 8 (Exposure Controls/Personal Protection). While the SDS might suggest glove types, you should always double-check this against the manufacturer’s specific permeation and degradation data for the glove you plan to use with those exact chemicals. Look for gloves rated Type A, B, or C depending on the number and types of chemicals, making sure the glove’s letter codes cover the hazards you’ll encounter.

Considering exposure duration and breakthrough time needs

Figure out how long contact with the chemical(s) might last. Compare this needed protection time with the glove’s reported Breakthrough Time (BTT) performance levels for those chemicals. Aim for a glove with a BTT considerably longer than your expected exposure, building in a safety buffer. Keep in mind that lab BTTs reflect ideal scenarios; real-world protection times can be shorter due to factors like temperature, pressure, and glove flexing.

Balancing protection with dexterity and material choice

Think about what the task demands. Thicker gloves usually last longer against chemicals but can make it harder to feel and move your fingers, possibly increasing risks during delicate work. Look into different glove materials (like nitrile, neoprene, butyl, or viton) because they resist different chemical families differently. Also, consider allergies; nitrile gloves are a popular choice for people sensitive to latex. Try to pick the thinnest glove that still gives you the chemical resistance and dexterity you need.

Why is regular inspection and proper replacement vital?

Even the perfect glove won’t protect you if it’s damaged. Before every use, check gloves carefully for any signs of wear or tear (pinholes, rips, changes in color, swelling, stiffness) or previous contamination. Always follow the manufacturer’s advice on reuse; single-use gloves should absolutely never be reused. If you have reusable gloves, clean them as instructed and replace them regularly based on how much you use them, any visible degradation, or the manufacturer’s advice, including paying attention to any listed expiry date. Consistent inspection and timely replacement are crucial for keeping that protective barrier intact.