Pesticide Labeling and Safety Data Sheets
Read the label in order
Every label follows a predictable architecture: brand and type, ingredient statement (active ingredients first, then inerts), signal word, precautionary statements (human and domestic animal hazards, PPE, environmental hazards, physical/chemical hazards), directions for use (sites, pests, rates, timing, PHI, REI, tank mixes), storage and disposal, and the misuse statement.
Signal words
DANGER-POISON with the skull and crossbones is Category I, the most acutely toxic (oral LD50 at or below 50 mg/kg). DANGER alone is Category I for severe eye or skin damage or high dermal toxicity. WARNING is Category II. CAUTION is Categories III and IV. Trap: ranking WARNING above DANGER under time pressure, or treating CAUTION as 'safe.'
REI and PHI
The restricted-entry interval is the minimum time after application before workers may enter without PPE. The preharvest interval is the minimum time before harvest. They are independent, label-specific numbers. Rain or a dried spray deposit does not shorten an REI.
Safety Data Sheets
Under OSHA HazCom, SDSs have 16 fixed sections. Section 2 is hazard identification, Section 4 first aid, Section 8 exposure controls and PPE, Section 9 physical properties. The SDS supports the label but never overrides it. Keep one accessible for every product on site and in the service vehicle.
Worked example
A label specifies a 12-hour REI and your crew wants to irrigate 4 hours after the application. They may not enter unless the label provides an early-entry exception with specified PPE and time limits. Answer from the label text, not from convenience.
Trap
Some deviations are legal because the label itself permits them - a rate range, a listed tank mix, a specified application method. Anything outside those allowances is a violation.