This demonstration video illustrates the potential ignition of cotton undergarments using a cotton bra. OSHA, NFPA 70E and CSA Z462 all require that workers not wear melting materials, even in underwear, excluding “incidental elastic”.
e-Hazard has investigated two accidents in which bras melted or ignited under flame resistant clothing. It is recommended to never use a melting undergarment. Instead, use the arc rated shirt no more than its rating or use an arc rated bra, which can be purchased at ArcStore.