To support a safe work environment, OSHA regulations monitor every aspect of a commercial business including fire protection.  Under 29 CFR 1910.157 fire extinguishers are to be visually inspected monthly.   29 CFR 1910.157 also requires the fire extinguishers to receive an annual maintenance check by a certified fire protection company.  Failure to comply with these  regulations can lead to employers paying expensive fines and closing the business until the issues are resolved.

Be prepared for OSHA