
Until 1978, when the U.S. Consumer Product Safety Commission (CPSC) phased out the sale and distribution of residential paint containing lead, many homes and businesses were treated with paint containing some amount of lead.
If you own or manage a residential rental property built before 1978 there is a good chance that at least some of the walls and surfaces were originally painted with lead based paint.
Through the 1900's, it was common practice to use lead pipes for interior plumbing. Lead piping was also used for the service connections that join buildings to the public water supply. This practice only recently ended in some localities.
OSHA has established exposure standards for general contractors working on a site that contains LBP under 29 CFR 1926.62. According to this regulation, workers must not be exposed to greater than the Permissible Exposure Limit (PEL) of fifty micrograms per cubic meter (50 mg/m3).