Application for the Reassessment of a Hazardous Substance under ...

abcdefgUK CRD Guidance for Post-Application (Re-Entry Worker) Exposure Assessment (UK CRD, 2008a), with cereals TC from US EPA (US EPA, 2000);D (dermal exposure) = DFR x TC x DA x WR x AR x P / BWWhere: DFR = 0.5 μg a.s./cm² per kg a.s./ha (Casida et al., 1962 in APVMA, 2008b);DA = percentage dermal absorption (30%); BW = bodyweight (70 kg); WR = 8 hours/dayP = Penetration Factor for Clothing [= 1 which assumes one layer of ordinary clothing is taken into account; or 0.05 for PPE: hood/visor + overalls over long-sleevedshirt and long-legged trousers + boots + gloves]I (inhalation exposure) = mg a.s./hr inhaled x WR / BWWhere: mg a.s./hr inhaled = kg/a.s./ha applied x Task Specific Factor; 50% volatilisation assumed (Casida et al., 1962 in APVMA, 2008b);Task Specific Factor: Berries/Fruit, Vegetables/Cereals, 0.01;P for RPE (% penetration): none, 1 (100%); half-face respirator, 0.1 (10%); full-face, 0.02 (2%); air-hose/SCBA, nil exposure (0%) – RPE is full-face respirator unlessotherwise stated (Thongsinthusak et al., 1993 in APVMA, 2008b);RQ = Total Estimated Occupational Exposure / AOEL where AOEL = 1.4 μg/kg b.w./day RQ > 1 indicates the likelihood of an unacceptable risk to those exposed;Assumes 1 or 2 treatments per year (7 days between applications), with complete dissipation between repeat applications;Half-face respirator;Air-hose/SCBA (Scenarios 1 & 2 RQs would also be unacceptable with Air-hose/SCBA).Dichlorvos reassessment – application Page 314 of 436