Asbestos has not been used in Australia since 2004 but is still present in older buildings, structures and products. Asbestos poses a health risk if the material is broken, deteriorating or disturbed to produce dust containing asbestos fibres.
Wearing protective clothing is therefore key to reducing the risks associated with handling asbestos. Cross contamination occurs when asbestos fibres attached to a person’s skin or underwear are carried to uncontaminated places, released and then inhaled. To avoid cross contamination, protective coveralls must provide a high barrier against airborne particles.
They must have high particle barrier; smooth surface to prevent particles from adhering to the garment; tight fit at arm and leg openings; compatible with additional PPE and be comfortable to wear with a high freedom of movement.
Dupont has developed Tyvek which is noted for its high abrasion and tear resistance. Tyvek is also lightweight and soft, as well as permeable to both air and water vapour, providing a high level of wear comfort.
Due to its smooth surface and antistatic treatment, Tyvek prevents particles from adhering to the coverall. If the particles do not adhere to the coverall easily, there will be less secondary inhalation.
When comparing their barrier performance with other Type 5 suits made of Microporous Film (MPF) and SMS (Spunbond/Meltblown/Spunbond) to those made of Tyvek, the models made of Tyvek show a significantly lower Average Total Inward Leakage (TILa) according to EN ISO 13982-2 with an average value of less than 1%.
The Type 5 product standard allows for an inward leakage of up to 15% in 8 out of 10 suits tested. Therefore, Tyvek Classic Xpert provides the better protection against fine particle hazards.
When testing inward leakage, a person wearing the protective suit enters a “testing chamber”. Beneath the suit, the person has three measuring probes attached.
Sodium chloride particulates (average size of 0.6 microns) are distributed throughout the chamber and the wearer performs a series of three physical activities:
• 3 minutes standing
• 3 minutes “on the spot” walking (5 km/h)
• 3 minutes squatting (rate of 5 squats per minute)
Sodium chloride particulates that penetrate the protective suit are counted by the probes beneath the suit. The amount of sodium chloride detected by each probe (per suit per exercise type) is expressed as a percentage ratio vs. the concentration of the “external” challenge of particulates.