Growers planning to use chlorpyrifos (Lorsban) will face a significant new restriction on its use.
Due to concerns about adverse effects of chlorpyrifos on children, the California Department of Pesticide Regulation (CDPR) has released 
recommended permit conditions for chlorpyrifos that would require application setback distances from sensitive sites of up to 500 feet. The distance of the buffer to a sensitive site varies by the method of application, whether airblast or aerial, and the amount applied. The Interim Directive has been distributed to County Agricultural Commissioners. Therefore, when using chlorpyrifos, restricted material permit conditions should be confirmed with the local Ag Commissioner, as they may have changed.
The chlorpyrifos recommendations are interim, pending completion of a review of this pesticide’s potential listing as a Toxic Air Contaminant. The recommendations are aimed at minimizing bystander exposure and offsite movement of chlorpyrifos during applications and reducing runoff after application. Sensitive locations are areas frequented by non-occupational bystanders (especially children) and include “residential lawns, pedestrian sidewalks, outdoor recreational areas such as school grounds, athletic fields, parks and all property associated with buildings occupied by humans for residential or commercial purposes,” according to CDPR’s Revised Interim Permit Conditions. Specific examples are homes, farmworker housing, other residential buildings, schools, daycare centers, nursing homes and hospitals. Non-residential agricultural buildings, including barns, livestock facilities and sheds, are not included in the prohibition.
The interim permit conditions were released on the same day as public comments were due on the potential listing of chlorpyrifos as a Toxic Air Contaminant, drawing concern in comments from the Almond Alliance of California. Comments from the Almond Alliance addressed the use of epidemiological data in the assessment. They also noted the important role of chlorpyrifos as part of a broad Integrated Pest Management (IPM) tool kit. This was well documented in a report funded by CDPR, Identifying and Managing Critical Uses of Chlorpyrifos Against Key Pests of Alfalfa, Almonds, Citrus and Cotton.
