Pesticide Labeling and Safety Data Sheets
The label is the legal instrument of pesticide use and the single most tested document on the exam. Candidates must be able to read a label and locate: the product name and registration number, active and inert ingredients, signal word and precautionary statements, first aid, directions for use (sites, rates, timing, application methods), restricted-entry intervals (REIs), personal protective equipment (PPE), storage and disposal, and environmental hazards. The signal word ranks acute toxicity: DANGER-POISON (with skull and crossbones) for the most acutely toxic, DANGER for severe hazard (corrosive or strong irritant), WARNING for moderate, and CAUTION for low toxicity.
A Safety Data Sheet (SDS) is a 16-section document supplied by the manufacturer under the hazard communication framework. It provides hazard, handling, and emergency information but is not a substitute for the label; the label governs use. Know that Section 4 covers first aid, Section 8 covers exposure controls/PPE, and Section 9 covers physical properties.
Traps: Questions may present an SDS as the legal use document (it is not), or ask whether a label can be altered (it cannot). Another trap: the REI is a time during which entry is prohibited without required PPE, and it is separate from the preharvest interval (PHI). Also watch for questions about supplemental labeling and special local needs (SLN, Section 24(c)) labels, which authorize state-specific uses.
Rule of thumb: If the label and the SDS disagree about a use, the label wins; if the label is silent, do not assume permission.
Worked example: A label lists a 12-hour REI and a signal word of WARNING. After a morning application, a worker wants to scout the field after 6 hours. The REI prohibits entry until 12 hours pass unless the label's early-entry PPE is worn.