He was a co-sponsor of the McAteer-Petris Act which established and governs operations of the San Francisco Bay Conservation and Development Commission (BCDC).

[4] During his terms in the State Assembly, Petris became concerned with constituent reports about air pollution.

Although it received little support, he modified the language of the bill to instead ban the sale of gasoline-powered cars from 1975 onward.

In March 1969, Petris re-introduced the bill in the Senate's health committee, where it received a unanimous endorsement and grassroots support.

Petris later supported emissions regulations by the California Air Resources Board which forced auto manufacturers to adopt the catalytic converter.