The protection factor measures the protection provided to the wearer and indicates the efficiency of the respirator in reducing airborne contaminants inhaled. Air-purifying respirator cartridges or canisters have a limited capacity to protect against toxic gases and vapors in the air. Then inspect your respirator for any physical failure. You must change the respirator cartridge or canister if you detect no physical problems. Do not use these respirators in situations where the oxygen content of the air might be low.
Respirators only protect from inhalation exposure.
For many situations when pesticides are used, protection from dermal exposure may also be necessary. Some sources are listed for your use. Safety equipment retailers - see local telephone directory yellow pages. Occupational safety and health consultants. County Agricultural Commissioner - see listing under County Government Offices, Agricultural Commissioner.