OSHA also took on the passive smoking fraud and this is what came of it:


Reference Manual on Scientific Evidence: Third Edition 



 This sorta says it all 

 These limits generally are based on assessments of health risk and calculations of concentrations that are associated with what the regulators believe to be negligibly small risks. The calculations are made after first identifying the total dose of a chemical that is safe (poses a negligible risk) and then determining the concentration of that chemical in the medium of concern that should not be exceeded if exposed individuals (typically those at the high end of media contact) are not to incur a dose greater than the safe one. 

 So OSHA standards are what is the guideline for what is acceptable ''SAFE LEVELS''