Chemicals pose a danger to many workers in the workplace, even though most workers don’t understand chemical risks too well or how to protect themselves properly. This leads to misconceptions like ‘chemical proof’ clothing when the truth is that not all chemical suits offer the same level of protection. The selection of chemical suits can seem rather daunting at first but we are here to help. It all starts with three basic elements.
The first step is to determine which fabric material you should be using to protect against the expected chemical hazard(s). To do this, you will want to take the list of chemicals that you may come in contact with and compare them with manufacturer testing. Permeation data is the most common type of testing and the higher the number, the better. Permeation is the ability of a chemical to be absorbed or diffuse through the material which is important to keeping the chemical on the outside of the suit.
There are four main types of seams on chemical suits:
- Serged or Stitched Seam: joins two pieces of material with a thread stitch that interlocks. This is economical and generally not used for chemical protective clothing. It is more commonly found on limited use clothing where dry particulates are of a concern.
- Bound Seam: joins two pieces of material with an overlay of similar material and is chain stitched through all of the layers for a clean finished edge. This provides increased protection against light liquid splashes and dry particulates.
- Heat Sealed/Taped Seam: seams are sewn and then sealed with a heat activated tape or can also be ultrasonically welded. This method provides liquid proof seams, and is especially useful for Level A and B chemical protective clothing as there are no holes in the suit for chemical penetration.
- Heat Sealed Plus Double Taped: the strongest seam. The seam is sewn and then heat sealed on the outside and inside to offer the highest strength and chemical resistance. This is the highest level of protection that you can get as it is double the protection against chemical penetration.
When choosing the right seam, consider the likelihood of a splash and the severity of the chemical product you will come in contact with. For example, large dry particles are good with stitched seams while hazmat response or chemicals spray under pressure applications are better suited for double taped seams.
Type of Exposure
Determining the type of exposure you have also plays into which material you need to select for chemical suits. It is important to consider the likelihood of a splash, the severity of the chemical product and the likelihood of the chemical product entering the suit.
If you have a light splash risk with short exposure time, you don’t need a chemical suit made of the best material. A lighter material can be used so you will have better airflow in the suit and it won’t be as heavy which leads to less discomfort, especially in warmer temperatures.
But, if you are performing work with your arms immersed in chemical for extended periods of time or with very aggressive chemical products, you’ll need to pay very close attention to the permeation rates and likely want a suit with double sealed seams.
Additional information including a breakdown of the different levels designated by the EPA (Suit Levels A-D) can be found by clicking here.