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

Conclusions on operator exposure estimates and risk assessment4.35 Scenarios 1-16 give unacceptable risks for operators (mixer/loader/applicators),even with PPE, RPE and engineering controls, where appropriate, except forScenarios (9 & 10) (automated fogging operations with RTU gas in glasshouses insome cases) and Scenarios (13 & 14) (automated fogging with EC solutions inCymbidium production, with restrictions). No outdoor uses of dichlorvos instrawberries, vegetables, cereal berries, fruit trees or passion fruit gave acceptableoperator risk estimates (Scenarios 1-8).4.36 Vegetables/Mushrooms: RTU dichlorvos gas through automatic spray systems at50 mg/m 3 may be used for the fogging of glasshouse crops/ mushrooms(Scenarios 9 & 10), provided: work day exposure is limited to the use of only onedichlorvos gas cylinder, and half-face respirator, chemical-resistant gloves,overalls, eye protection and boots are worn. Two dichlorvos gas cylinders, as amaximum, can be handled in a day (see Table VI) provided: a full-face respirator,chemical-resistant gloves, overalls, eye protection and boots are worn duringcylinder changeover. The cylinder change over restriction means that only small(approximately 0.25 ha) spaces can be treated with 7 L cylinders, but treatment oflarger spaces (up to 1.25 ha) is possible using 35L cylinders using automatedsystems.4.37 Cymbidium: EC dichlorvos solutions through automatic spray systems at 1.3kga.i./ha may be used for fogging glasshouses during Cymbidium production(Scenarios 13 & 14), provided: work day exposure is limited to 0.1ha (1,000m 2 ),and a respirator of at least A1P2 specification, eye protection and chemicalresistant gloves are worn during mixing/loading. Automated treatment or manualfine spray application at 1.8 kg a.i./ha in glasshouses for Cymbidium productiondo not give acceptable risk estimates.4.38 As can be seen from Tables VI-VIII above, some of the enclosed spaceapplications give acceptable risks for operators if adequate PPE and RPE areworn. In some cases the length of work exposure (area/volume treated) also needsto be limited.4.39 RTU dichlorvos gas through automatic spray systems at 50 mg/m 3 may be usedfor the fogging of enclosed industrial spaces of 375 or 3750 m 3 (Scenarios 17 &18; Table VI), provided: work day exposure is limited to the use of only onedichlorvos gas cylinder, and half-face respirator, chemical-resistant gloves,overalls, eye protection and boots are worn during cylinder changeover. RTUdichlorvos gas through automatic spray systems at 50 mg/m 3 may be used for thefogging of enclosed industrial spaces of 12500 m 3 (Scenarios 17 & 18), provided:work day exposure is limited to the use of only two dichlorvos gas cylinders, andfull-face respirator, chemical-resistant gloves, overalls, eye protection and bootsare worn during cylinder changeover. Thus Scenarios 17 and 18 give acceptablerisk estimates for all treatment volumes, provided sufficient PPE/RPE is worn.4.40 Application of RTU dichlorvos gas at 50 mg/m 3 may be used for the manualfogging of enclosed industrial spaces of 375 m 3 (Scenarios 19; Table VI),Dichlorvos reassessment – application Page 306 of 436