Vinyl chloride respirators, including all completely assembled respirators which are designed for use as respiratory protection during entry into and escape from vinyl chloride atmospheres containing adequate oxygen to support life, are described according to their construction as follows:
(a) Front-mounted or back-mounted gas masks;
(b) Chin-style gas masks;
(c) Chemical-cartridge respirators;
(d) Powered air-purifying respirators; and
(e) Other devices, including combination respirators.