What is static electricity?
Static electricity refers to the build up of an electric charge on the surface of objects. The static charge remains on an object until it either bleeds off to ground or is quickly neutralized by a discharge. The effects of static electricity are familiar to most people because we can feel, hear, and even see the spark as the excess charge is neutralized when brought close to a large path to ground. The familiar phenomenon of a static ‘shock’ is caused by the neutralization of charge. Static electricity can be considered either a nuisance in the form of the garment clinging to your body or an actual hazard from sparking in a flammable atmosphere. The main source of spark potential comes from static charges stored in the body of an ungrounded worker rather than from garments.
Static Electricity on Garments
The generation of static electricity on clothing depends on a number of factors: the type of fabric, the relative humidity, the fabrics ability to absorb moisture, the task being performed, and the use or lack of use of grounding devices. The biggest factor is the moisture content of the fabric, as moisture allows the static charge to dissipate easier so it doesn’t build up. Under standard environmental conditions, synthetic fiber fabrics such as polyester, nylon or Nomex absorb less moisture and retain more static than natural fiber fabrics like cotton. The friction from fabric rubbing is the primary cause of static buildup. The action of donning or removing garments will generally increase the charge on the human body and provide a source for a static discharge.
Nomex IIIA & Protera
Nomex IIIA and Protera fabrics incorporate a static dissipative fiber. This helps dissipate static charges in the fabric which reduces the risks and discomfort associated with static electricity. It also reduces the contribution of clothing to the static buildup on the human body. This fiber does not totally eliminate static, so we always recommend that a user in a high risk environment use static dissipative wristlets or anklets that are available for this hazard.
Indura, Indura Ultra Soft & Tecasafe Plus
Indura, Indura Ultra Soft and Tecasafe Plus all contain fibers which readily absorb moisture (cotton or Lyocell). This ability to absorb moisture allows the static to dissipate easier. However in low humidity environments, the amount of available moisture may not be enough to affect the static electricity found in the garments.
Fabric Softeners & Anti Static Products?
Generally speaking, FR fabric manufacturers do not recommend using fabric softeners, dryer sheets or anti-static products that have not been tested for flammability. These products can leave a residue that may be flammable and would need to be tested.
- All fabrics have the ability to generate static electricity. FR garments are no more likely to generate static than other garments under the same conditions.
- Stored energy on the body of an ungrounded person is really the primary source of static electricity.
- Do not don or remove garments in a hazardous atmosphere
- If in an environment where a static discharge could be hazardous, use engineering controls like static dissipative wristlets or anklets or other grounding methods that are available for this hazard.