The first three strategies focus on doing something with the hazard.
Elimination: The best solution is to totally eliminate hazardous substances in the workplace
Substitution: Substitution is the next-best solution. Replace a toxic substance with a less-toxic substance. If you can't get rid of the toxic substances, you may be able to replace them with substances that are at least less toxic.
Engineering Controls: Redesign or modify processes that use toxic chemicals to eliminate or reduce exposure to the chemical hazard itself.
The last two strategies focus on doing something with behaviors to reduce exposure to the hazard.
Administrative Controls: Change work procedures to reduce the duration, frequency, and severity of exposure to the chemical hazard. The chemical hazard is not eliminated or reduced using this strategy. The primary focus is to incorporate safer work practices through written safety policies, rules, supervision and training. And that's a problem because you may have to regularly supervise employees as they perform a task. These controls work only so long as employees "behave" properly.
Personal Protective Equipment (PPE): The use of PPE is probably the most common strategy, and mandatory when working with hazardous chemicals. PPE forms a barrier between worker and hazard. Once again, the chemical hazard is neither eliminated nor reduced, and a high reliance is placed on appropriate use of PPE for this strategy to be successful.