Cal. Civ. Code § 127C

Section 127C. If the condition of any building or any part thereof used for residential purposes is in violation of the standards of fitness for human habitation established under the state sanitary code, as provided by section one hundred and twenty-seven A, or in violation of any board of health standards, a petition may be filed by any affected tenant or by the board of health, or, in the cities of Boston, Worcester and Cambridge, by the commissioner of housing inspection, in a district court, housing court, or superior court. The petition shall state that the premises have been inspected by the board of health or other appropriate inspection agency and that the condition of said premises has been found to be in violation of the state sanitary code; that such condition may endanger or materially impair the health or well-being of any tenant therein; and that said condition was not substantially caused by the tenant or any other person acting under his control.

An affected tenant may also file a petition in such court without stating that such premises have been found by an appropriate inspection agency to be in violation of any such standards, provided that he states (a) facts sufficient to demonstrate a likely violation of the state sanitary code which may endanger or materially impair the health or well-being of any tenant in the building or premises occupied by such tenant, (b) that the conditions in question were not substantially caused by such tenant or any person acting under his control and (c) that a request for inspection of such premises was made to the appropriate inspecting agency at least twenty-four hours prior to the filing of the petition and that there has been no inspection.