The Probabilistic Exposure and Risk Model for FUMigants (PERFUM) was developed by Dr. Richard Reiss and Mr. John Griffin at Exponent to address the issue of bystander exposures to fumigants following agricultural applications. Following application of fumigants, some of the applied material may volatilize from the field and be carried downwind, causing potential exposure to persons in the vicinity of the application. The highest exposures will be closest to the field, with the atmosphere dispersing the fumigant gas to lower concentrations as the plume moves downwind. The model was developed to address the regulatory need to establish buffer zones for some fumigants. The purpose of a buffer zone is to define a distance from the edge of the field where the concentration of the fumigant is at or below a level assumed to be safe.
The first version of PERFUM was submitted to the U.S. EPA in the summer of 2004. EPA convened a FIFRA Scientific Advisory Panel (SAP) meeting to review the model in August of 2004. The SAP meeting was held on August 24-25, 2004, and the review can be found on the EPA website along with a detailed report on the model. The SAP found the model to be “scientifically sound.” The model has been updated several times since the SAP. The latest version of the model includes expanded capabilities for modeling agricultural fields, including the consideration of multiple fields emitting simultaneously. Additionally, the model includes new algorithms for estimating buffer zones for applications within buildings (e.g., greenhouses, commodity warehouses). In June 2006, a peer-reviewed article describing the model was published by Reiss and Griffin in Atmospheric Environment
The current version of the model is version 2.5. The download below includes all of the files needed to run PERFUM, and also includes a user’s manual. Users should download the file into a directory called PERFUM2, and unzip the compressed download file to unpack all of the program files and set up the required subdirectory structure.
PERFUM was developed and is being supported with funding sponsorship from Arysta LifeSciences Corporation.
Version Control (PDF)
(updated July 2008)Download PERFUM
(zip file)User's Guide (PDF)