These guides cover environmental concerns in homes, workplaces, and public buildings throughout California. Start with the basics, understand the testing options, and learn which state and local requirements may apply to your project.
What would you like to understand?
Mold growth on a wall surface. Finding and correcting the moisture source is part of addressing the problem.
Multiple deteriorated paint layers on wood. Testing is needed to determine whether a painted surface contains lead; color and appearance cannot answer that question.
Our guides link directly to EPA, CDC, California agencies, and air district programs. Look for the source links beside the explanations and use the California air district directory to find local requirements. Health guidance, building assessments, and project regulations answer different questions; the guides explain those distinctions.
Sources checked September 9, 2026. Confirm current requirements with the agency responsible for your project.
Your questions are welcome
Let’s talk about your property.
You don’t have to choose a test on your own. Tell us what you’ve noticed or what work you’re planning, and we’ll help you understand the next step.
