Nomex IIIA and cotton FR (Pyrovatex, etc) are both flame-resistant fabrics that are used in the manufacture of workwear. However, there are some significant differences between the two fabrics, including their flame resistance properties, durability, and washability.
Nomex IIIA is a type of aramid fabric that is made by DuPont. It is known for its excellent flame resistance and thermal insulation properties. It is a lightweight fabric that is comfortable to wear, and it is often used in the manufacture of workwear for industries such as oil and gas, electric utilities, and firefighters. Nomex IIIA is also known for its durability and resistance to shrinking and fading.
Cotton FR, on the other hand, is a fabric that is made from cotton that has been treated with a flame-resistant chemical. Cotton FR is known for being comfortable to wear and for its breathability. However, its flame resistance properties are not as good as Nomex IIIA. Cotton FR is often used in the manufacture of workwear for industries such as welding and metallurgy.
In terms of washability, Nomex IIIA is known to be more durable and can withstand multiple washes without losing its flame-resistant properties, while cotton FR may lose some of its flame-resistant properties over time and after multiple washes. It is important to follow the care instructions provided by the manufacturer to maintain the flame resistance properties of both fabrics.
In summary, Nomex IIIA and cotton FR are both flame-resistant fabrics that are used in the manufacture of workwear. Nomex IIIA is known for its excellent flame resistance and thermal insulation properties, durability, and resistance to shrinking and fading while Cotton FR is known for being comfortable to wear and its breathability but with less flame resistance properties. Nomex IIIA is more durable and can withstand multiple washes without losing its flame resistance properties, while cotton FR may lose some of its flame resistance properties over time and after multiple washes.
See our range of Nomex and other FR workwear here. 
