EN standards define 5 “Types” of application-based chemical protective clothing. But what do they mean and how do they differ from North American OSHA protection levels?

For a global business looking to standardize PPE in every regional base the need to meet multiple local standards and conventions is a challenge. When managing hazardous chemicals in the workplace an understanding of the differences between regions can be useful. This blog aims to explain the chemical protective clothing Types defined by EN standards, the OSHA Protection Level guidance used in North America, and to show where they are different or similar.

EN Standards for Types of Protective Clothing

The system launched in the European Economic Community in 1995 aimed to improve the levels of protection against workplace hazards by introducing a legal requirement that all PPE should meet minimum performance requirements. This was achieved through the publication of standards for PPE performance, with compulsory compliance being independently audited and approved by appointed “Notified Bodies”, and indicated on PPE labels by the now well-known CE mark.

For chemical protective clothing several CE standards define performance requirements according to the hazard; it’s state: liquid, dust, or gas, and in the case of liquids: light aerosol, liquid, or jet sprays. These define 5 “Types” of clothing according to level and type of protection provided.

Meanwhile in North America no such mandatory or optional standards exist for chemical protective clothing. However, OSHA, the Occupational Safety & Health Administration, the government agency charged with “ensuring safe and healthful conditions for workers” has issued four “Protection Levels” as guidance for choosing PPE for protection against hazardous materials in the workplace.

The PPE or the Hazard? An Important Difference

A key difference between the approaches of Europe and America is that whilst European chemical suit standards focus product – in this case clothing that protects the skin of the wearer, with respiratory and ingestion hazards dealt with by other standards, the protection levels in America address whole body protection including, and treating as primary, protection against respiratory hazards. Thus, the OSHA levels address all the required PPE, considering respiratory protection as paramount, whilst the EN standards have different standards for different PPE.

This means direct comparison of the EN standards and OSHA protection levels is difficult; there are no direct equivalents. However, below is an analysis of both and a summary of how they compare.

EN Standards for Chemical Resistant Protective Clothing

In EN standards all PPE is classified as follows: –

The key standards for chemical protective clothing are: –

Garments certified to either one or more of these standards must display the specific pictogram below to indicate “chemical protection” on the label.

However, in addition many manufacturers also use the pictograms shown in the table below to indicate the Type of clothing. Note that these Type-specific pictograms are not required by the standards but are a convention adopted by many, though not all, manufacturers. Some prefer to use their own symbols. The standards do, however, require the “Type”, standard number and date is referenced on garment label.

How is Chemical Resistant Clothing Tested?

The process for certification of clothing to these standards includes three types of testing:-

The test and assessment criteria for each Chemical Protective Clothing Type is shown below: –

Type 5: Type Test for Clothing for Dust Protection

• The test subject stands on a treadmill and performs three “movements” during the test: walking, squatting and standing still.
• Three sensors inside the suit measure particles that penetrate, whilst a fourth outside in the cabin produces a “challenge count”.
• Using this information calculations of “Inward leakage” are made for each sensor and during each movement.
• Pass or fail is defined according to specific criteria for the inward leakage.

It is worth noting that a pass does NOT mean no penetration has occurred. Allowance is made for some penetration of the dust.

Protection against Hazardous Liquid Chemicals

For Types 3,4 and 6 liquid protection, the test subject wears a white, absorbent coverall underneath the test garment. Because this stains easily it acts as an indicator of penetration. The liquid used is is water and is the same in each test: –

• Its surface tension is lowered using a surfactant. This increases its tendency to wick through any small holes in the garment construction so making the test more challenging.
• It is died red so that any staining of the absorbent under-garment will be apparent.

Type 6: Type Test for Clothing for Liquid Aerosol Protection

• The test subject stands on a turntable that rotates once in one minute
• As the turntable rotates, the subject makes an exaggerated walking motion. This ensures exposure of the liquid to all parts of the garments
• Four nozzles at a distance of 1.5M from the center of the turntable spray the garment with an aerosol of the test liquid for one minute as the turntable rotates.
• The garment is then allowed to drain for two minutes and carefully removed.
• The total area of any staining of the indicator garment of three tests is measured and a pass or fail calculated

Type 4: Type Test for Clothing for Liquid (shower-type) Sprays

• The test subject stands on a turntable that rotates once in one minute
• As the turntable rotates, the subject makes an exaggerated walking motion. This ensures exposure of the liquid to all parts of the garments
• Four nozzles at a distance of 1.5M from the center of the turntable spray the garment with a liquid spray (of the type and pressure of a standard shower head) of the test liquid.
• The garment is then allowed to drain for two minutes and carefully removed.
• The total area of any staining of the indicator garment of three tests is measured and pass or fail calculated

Type 3: Type Test for Clothing for Liquid Jet Sprays

• The test subject stands motionless as indicated by the test supervisor.
• A single jet nozzle issuing a pressurized stream of the liquid is sprayed horizontally at “potential weak spots” of the suit as directed by the operator. The distance between the nozzle and contact with the suit is maintained at 1 meter
• “Weak spots” are defined as areas that may be more susceptible to penetration such as seams, points where seams join (such as the back of the neck, the crotch and under the arms), and zip covers. The jet spray will be directed at an angle to the zip flap intended to force the flap open.
• The operator directs the test subject to stand motionless in positions to allow access to the spray points.
• Each individual spray is for 5 seconds. No specific number of sprays is defined; the selection is determined by the test operator.
• The garment is then allowed to drain for two minutes and carefully removed.
• The total area of any staining of the indicator garment of three tests is measured and a pass or fail calculated

Type 1: Test for Gas-Tight Clothing for Gases and Vapors

For suits for protection against gases and vapors, the key test is of a different format. The suit is inflated to a specific pressure and then left for 5 minutes to allow equalization. The pressure is then monitored for a period of 3 minutes, and the pressure within the suit must not drop more than a specified amount.

Thus the Type 1 internal pressure test is measuring the leakage of the suit under pressure as an indication that it is air tight, and so will not allow penetration of air, vapors or gases into it.

The requirements for Type 1, part garments for Emergency Teams also includes an inward leakage test similar to the Type 5 dust test. Type 1 garments also require a practical performance test with the pressure test conducted before and after.

How useful are the Type Tests?

The EN standard “Type Tests” provide an indication of the effectiveness of protection offered in simulations of real-world liquid spray and dust hazards. Understanding of these tests is useful in identifying the types of applications that the different suits may be suitable for. and in recognizing the different properties of the suits. In fact the tests do have specific implications for the construction and design of garments: –

• The movement tests mean that a poorly designed or small sized garment is likely to split even before the sprays tests are conducted.
• The pressure of spray in the Type 3 test means that only a garment featuring barrier film and sealed seams will pass.
• Whilst a pervious fabric (such as a microporous film) may, subject to quality, pass the Type 4 test, unless the garment is constructed with sealed (not stitched) seams it will fail.
• The pressure and direction of the Type 3 test and the volume of liquid in the Type 4 test means a garment must have a very effective and secure front fastening. A simple zip with single zip flap is unlikely to pass. (Lakeland’s Super-B style garments feature a double zip & storm flap).

Thus, the Type Tests, as well as indicating general performance, by default produce particular requirements for garment design and construction, (such as sealed seams for Type 3 and 4 garments) even though those requirements are not made explicitly in the standards.

Do the Type Tests indicate the liquid pressure a garment will resist?

Contrary to the belief of many, the liquid standards do not specify a pressure of liquid on the garment. The pressure of the liquid in the spray nozzle is defined, but this is purely to achieve the correct type of spray and is not an indication of the pressure at which the liquid hits the garment. In fact, the specified nozzle pressure for Type 4 is twice that of the pressure for Type 3, despite the fact that in the Type 3 test the pressure of liquid as it hits the garment is far greater. This seems counter-intuitive, but is explain Write a review Your Name Your Review Note: HTML is not translated! Rating     Bad           Good Captcha Enter the code in the box below Continue retail @wholesale price servicing of equipment available rental of equipment available × Quote Cart Your quote cart is empty! Continue