Below is a list of Class 1000 Clean Rooms manufacturers from San Carlos, California. Class 1,000 clean rooms are rooms in which the concentration level of airborne particles is controlled so that they never exceed 1,000 particles per cubic foot. Class 1,000 clean rooms are the second lowest classification in Federal Standard 209 standards. The International Organization for Standardization (ISO) equivalent standard of Class 1,000 clean rooms is ISO 6.