The waterproof fabric used in Masks For Healthcare Workers is polyester urethane laminate or PUL. Below are the washing and drying instructions.
- Put in laundry bag, use gentle cycle of washing machine OR handwash by soaking in Woolite for 30 minutes, then toss in the dryer on low tumble heat.
- It is recommended to use a zero residue detergent – liquid detergent preferably. Wash temperatures can be hot, between 145 and 165 degrees F (65 to 75 degrees C).
- DO NOT use bleach. If required non-chlorine oxygenated bleach can be used sparingly, provided the detergent should not already contain sodium percarbonate (the active ingredient in many oxygenated bleaches). The detergent must also not contain any Fabric softeners, Natural oils, Perfumes, Dyes, UV brighteners, Stain guard ingredients, Enzymes.
- DO NOT add washing soda, soda ash or soda crystals to the detergent. The use of vinegar and/or baking soda can together or individually cause delamination.
- To dry, toss in the dryer on low tumble heat.
- Dry on low tumble heat, at a temperature not more than 130 degrees F (50 degrees C). The use of drying sheets with fabric softeners is not recommended.
- DO NOT wring or iron on the film side. Any urethane film is affected by bleach, chlorine, and dry heat exceeding 130 degrees F.
- Exposure to sunlight affects the urethane film. The film will turn yellow and crack over time. When the UV index is high this can happen in as little as 10 hours.
Source: Prosoft PUL (polyurethane laminate) Fabrics