OSHA says Cloth Masks and Surgical Masks Don’t Work: https://www.osha.gov/SLTC/covid-19/

OSHA defines oxygen deficient atmosphere as below 19.5%
https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.1202

OSHA example of shipyard, where “oxygen deficient atmosphere is leading cause of fatalities:
https://www.osha.gov/SLTC/etools/shipyard/shiprepair/confinedspace/oxygendeficient.html

CAL-OSHA states, “Cloth face covers are not protective equipment and do not protect the person wearing a cloth face cover from COVID-19.”
https://www.osha.gov/SLTC/covid-19/covid-19-faq.html

File a workplace safety complaint:
https://www.dir.ca.gov/dosh/Complaint.htm