San Mateo County, CA Public Health Rules: Rodent Control (2026)

80, Rodent and Insect Control, bars any Person from occupying or maintaining a building, lot, premises, vehicle or other place in a condition that permits rodents, flies, fleas, lice, mosquitoes, cockroaches, ticks, bedbugs, or other vermin to breed or harbor there (Sec. 010). 020 separately forbids letting material accumulate that could harbor rodents unless it is elevated at least 18 inches above the floor or ground with a clear space underneath. Companion sections extend the same duty to fly-breeding material, which must be removed as often as necessary and sprayed with insecticide to the Health Officer's satisfaction (Sec.

030), and to stagnant water that breeds mosquitoes, which must be drained, filled, or chemically or biologically treated to the County Health Officer's satisfaction (Sec. 040). 050 defines 'rodent-proof' construction: gaps around doors and windows no wider than one-quarter inch, and exterior openings such as louver vents covered with corrosion-resistant wire mesh with openings no larger than one-quarter of one square inch. 060 applies that standard directly to commercial and industrial buildings used to manufacture, prepare, store, handle, sell or display food or food products for human or animal consumption: they must be of rodent-proof construction, and the County Health Officer decides whether the rodent-proofing is adequate and whether infestation exists or is likely.

The chapter dates to Ordinance No. 2413, adopted January 11, 1977, and sits within Title 4's public health and sanitation provisions administered by the County Health Officer.