The ONGUARD Chemical / Hazmat Kneeboot aka " Hazmax " are the Finest Boots Made For Hazardous Materials Handling. Use in situations involving dangerous chemicals, gasses or biological hazards and waste. Certified by S.E.I. to meet the requirements of NFPA 1991 Standard on Vapor-protective Ensembles for Hazardous materials Emergencies, 2005 edition, and additional requirements for chemical and biological agents.