42 C.F.R. § 84.192 Cartridges in parallel; resistance requirements.
Title 42 - Public Health
Where two or more cartridges are used in parallel, their resistance to airflow shall be essentially equal.
Title 42: Public Health
PART 84—APPROVAL OF RESPIRATORY PROTECTIVE DEVICES
Subpart L—Chemical Cartridge Respirators
§ 84.192 Cartridges in parallel; resistance requirements.