What Does Disposable Coveralls Mean?
pd11ing10 > 11-10-2021, 07:31 AM
What Does Disposable Coveralls Mean?
Disposable coverall is an item of personal protective equipment (PPE) designed to cover the whole body and other clothing to protect against dirt or other outside contaminants. Coveralls are one piece and loose fitting for ease of movement, with sleeves, full leggings and often a hood to cover the head. These can also include overshoe pieces to cover footwear and protect against contamination.
Safeopedia Explains Disposable Coveralls
The purpose of using disposable materials to make coveralls is to avoid cost issues when using non-disposable materials which are certain to sustain damage when used situations that require coveralls very regularly, for harsh work conditions. Common materials used to make disposable gear are Tyvek, Polypropylene or Tychem. These materials have different safety ratings and properties which suit them to different environments. For example; some suits can be used in hazardous situations to protect from acid spills or hazard chemicals while some more breathable varieties may not. The American National Standards Institute (ANSI) and The Occupational Safety and Health Administration (OSHA) have provided regulations and standards for the design, testing and use of disposable coveralls which should be considered by employers while making a risk assessment, safety plan and choosing PPE.
Choosing the Right Disposable Coveralls
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:
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
- 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
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 like PP disposable coverall 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 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 disposable coverall is generally breathable with some air permeability.
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. Microporous disposable coverall isalso made of MPF.
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?
Benefits of disposable lab coats
Preventing chemical mixtures and limiting flammability
When a scientist wears a lab coat, spills and contamination of that coat are a fact of life. This means that, if a scientist is wearing the same lab coat every day, all day for a week, the chances that different chemicals with potentially adverse reactions combining on the coat become much higher. Even if a scientist wears the same lab coat all day, and cleans it each day, that risk is still there. When a new coat is worn every time the lab is entered, the odds of a chemical reaction due to what’s on the coat are next to zero. This seriously reduces risks of fire as well as physical risks to the scientist.
Preventing the spread of contagions
Throwing away a lab coat after every work session helps ensure that no diseases leave the lab or examination room. Lab coats must be cleaned, and often off-site. However, bringing an infected lab coat to a cleaning facility could start the spread of a new contagion. Even if the cleaning facility is on-site, that means more hands will need to touch the lab coat to clean or sterilize it between uses. This increases the risk of contagions on the coat spreading elsewhere.
Detergent, cleaner, and even cloth fibers from reusable lab coats can get into lab materials. If this happens, it can render a work session meaningless, or even worse, become a danger. Using a single-use lab coat ensures sterility every time that the lab is entered.
Easier to clean
Fabric lab coats need to be bleached to ensure that all contagions are killed. They also need to be thoroughly washed to ensure no contaminants are left after use. Disposable lab coat is usually made from plastic materials which are less porous than cloth fiber. They are easier to wipe down between uses, and can be washed easily with alcohol or bleach wipes to remove pathogens.
- 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