Portable fire extinguishers can be vital in preventing a small fire from turning into a major catastrophe. But the devices provide no protection if they are not properly maintained. OSHA offers the following rules regarding fire extinguishers:

• The employer is responsible for maintaining and testing all portable fire extinguishers in the workplace.
• Extinguishers or hoses must be visually inspected at least once a month.
• A full maintenance check should be performed on all extinguishers at least once annually, and records of this check should be kept for one year.
• Dry chemical extinguishers that require a 12-year hydrostatic test should be emptied for full maintenance every six years. Extinguishers with non-refillable disposable containers are exempt from this requirement. 
• Hydrostatic testing should be performed by trained individuals with suitable testing equipment and facilities.
• When portable extinguishers are removed for maintenance or recharging, the employer must provide an alternative that offers equal protection.