The hierarchy of control is an approach to minimize or eliminate hazards by: 1) Eliminating the hazard completely through removal or repair. 2) Substituting hazardous materials or processes with less hazardous ones. 3) Isolating hazards through guards, barriers or containment. 4) Using engineering controls like ventilation, insulation or machine guarding. 5) Implementing administrative controls through policies, training and supervision. 6) As a last resort, using personal protective equipment like ear plugs or gloves.