Choosing the Right Disposable Coveralls

This article explains some of the standards and classification systems for protective clothing. Specifically, it looks closely at disposable coveralls such as the kind used for protecting against chemical sprays or hazardous dusts like asbestos.

Why use protective clothing such as coveralls?

Workers can be exposed to many hazardous chemicals, mists and particles in the workplace. For example, asbestos is a well-known hazard, causing serious health issues such as mesothelioma and cancer. The smallest amount of inhaled asbestos can cause health problems, hence the stringent regulations and standards for handling asbestos in Australia.

In addition, many other harmful dusts and chemicals can be encountered on the work site. Many workplaces and workplace health and safety guidelines mandate that PPE including disposable protective coveralls be used for certain work processes.

In addition to handling asbestos, hazardous processes include working with chemicals, paint spraying, wood work, chemical manufacturing, environmental remediation, cleaning and fibreglass handling.

General guidelines for protective clothing

AS/NZS4501.2 covers general performance requirements for ergonomics, size and marking of protective clothing. It covers the information that manufacturers should supply, and specifies that protective clothing should not cause irritation or harm.

It’s important to note that if coveralls are not a single use disposable item, they must be properly decontaminated. This will help prevent particles or chemicals cross contaminating work processes, environments, and the worker’s regular work clothing.

Tests and standards for dusts, chemicals and particles

Protective coveralls are generally specified with a ‘Type’, which refers to a host of International Standards. These standards cover a wide range of individual performance tests that check for resistance against:

• Abrasion and cracking
• Tensile strength and tear resistance
• Resistance to punctures
• Resistance to chemical permeation
• Liquid repellence
• Resistance to spray and aerosols
• Resistance to ignition

Once the garment has passed a series of tests, it is classified into a type depending on its suitability for different applications.

Types of disposable coveralls

• Type 1 – Gas tight EN 943-1, EN943-2
• Type 2 - Non-Gas tight Garments EN 943-1
• Type 3 – Liquid tight EN14605, EN ISO17491-3
• Type 4 – Spray tight (saturation) EN 14605, EN ISO17491-4
• Type 5 – Protects against airborne particles EN ISO13982-1
• Type 6 – Protects against liquid chemicals (light spray) EN13034, EN ISO17491-4

Garments can also be classified as protecting against a range of hazards – for example, our Microchem 300 chemical splash suit is a Type 3, 4 and 5 coverall.

Type 1 refers to completely enclosed protective suits designed to protect against chemical contamination in the form of liquid or gas. Likewise, non-gas tight suits which retain positive pressure to prevent ingress of dusts, liquids & vapours are referred to as Type 2.

However, the most common classifications of protective coveralls in our industry are 3 through to 6 so let’s look at these in more detail.

Type 3 – Liquid tight

Type 3 coveralls have sealed seams rather than stitched. They must be made from a fabric that is liquid tight and can withstand strong directional jets of a liquid chemical during the test. Only a tiny fraction of liquid is allowed to enter the garment before it is deemed a ‘fail’. This is based on the breakthrough time of a strong jet of liquid at high pressure. The coverall can then be given a class, which relates to this breakthrough time: Class 1 is at the lower end of the scale with breakthrough taking just 10 minutes, whereas Class 6 resists ingress for over 6 hours.

Type 4 – Spray tight

Spray tight protective clothing is generally a coverall that protects against saturation of liquid chemicals. Both the fabric and the seams are rigorously tested where volume of the liquid builds up on the suit, causing pools and rivulets. Testing to meet Type 4 classification is similar to the above chemical test, but a lighter spray at a lower pressure – like a shower.

Type 5 – Protects against airborne particles

These garments are full-body protective items covering the trunk, arms and legs, such as one-piece coveralls or two-piece suits, which can be with or without hoods, visors and foot covers. These are tested to rate their resistance to dust and particles. They are suitable for processes such as light industrial cleaning, site preparation and handling insulation.

Type 5 rated coveralls are also suitable for asbestos work, provided they are disposable rather than reusable.

Coveralls that pass the test as Type 5 are subjected to a test subject performing a series of movements in the suit whilst it is exposed to a dry aerosol with a particle size of 0.6 μm. The inward leakage of the aerosol must be below a minimal threshold.

Type 6 - Light spray protection

This type covers suits that are for protection against light spray and splashes. It differs from the type 3 and 4 spray tests in that there is less volume of liquid sprayed, and no build-up of liquid on the suit. It is the lowest level of chemical protection and is intended to be used if risks have been assessed as low and a full liquid permeation barrier is not necessary.

Types of fabrics

Often protective coveralls are made from materials such as polypropylene, or trademarked fabrics such as Tyvek. They are often grouped under terms that refer to the way the fabric is constructed such as SMS or MPF.

SMS

SMS stands for spun bound / melt blown / spun bound fabric. This process uses a melt blown polypropylene layer sandwiched between two polypropylene layers. This results in a fabric that I strong and durable with strong barrier properties. SMS coveralls are generally breathable with some air permeability.

MPF

MPF is a microporous fabric made from a thin microporous film bonded to a spun bound polypropylene base. MPF fabrics are not as breathable due to their very low air permeability.

Choosing the right coveralls

There are so many variables in any individual application that it is difficult to be specific about what is best. Hence all protective clothing recommendations come with a disclaimer stating that it is the user’s final responsibility to ensure the garment is suitable for the application.

Every selection should begin with a risk analysis to determine the type of risk, the length of exposure and level of protection required. In general, key features to look for include:

• Is the level of protection suitable for the task?
• How robust or heavy duty are the coveralls?
• What is the quality like, including details such as the zipper, seams, fabric?
• What is the fit and comfort like? Will the size range be suitable for your workers?
• Are the coveralls single use? What should responsible disposal look like?
• Are they easy to put on and take off?

What can Jaybro supply?

Jaybro supplies disposable coveralls and overalls for asbestos work, and for general building, construction, infrastructure and cleaning tasks. Take a look at our range here or call our friendly team for advice and assistance in choosing the right disposable coveralls.