PHMSA uses risk management to prioritize compliance activity and address the risk associated with non-compliance. PHMSA places greater compliance emphasis on materials and packagings associated with materials presenting high hazard to the public such as poisons and flammable gases, explosives, and poison inhalation hazard liquids. When packagings are found in non-compliance, risk and benefit/cost assessments are used to determine if an appropriate course of action, such as recall, down-rating or use restriction, is necessary to protect public safety. PHMSA has developed a "Procedure for Removal of Nonconforming Hazardous Materials Packagings from Service" that delineates a process and assessment guidelines for nonconforming packagings.