Pesticide Management & Coordination
Pesticide-Use Risk Assessments and Worksheets
Risk Assessments
Forest managers frequently make decisions regarding the use of pesticides on forest lands. These decisions must be based not only on the effectiveness of these tools, but also on an understanding of the risks associated with their use. For the pesticides commonly used by the Forest Service in its management activities, Human Health and Ecological Risk Assessments (HERAs) are prepared.
Worker reading label prior to field work. Photo by USDA Forest Service - Region 8.
In these documents, the process of risk assessment is used to quantitatively evaluate the probability (i.e. risk) that a pesticide use might pose harm to humans or other species in the environment. It is the same assessment process used for regulation of allowable residues of pesticides in food, as well as safety evaluations of medicines, cosmetics, and other chemicals. The Forest Service incorporates relevant information from the HERA into environmental assessment documents prepared for pesticide projects, and are used to guide decision-making and to disclose to the public potential environmental effects.
Risk is defined as the likelihood that an effect (injury, disease, death or environmental damage) may result from a specific set of circumstances. It can be expressed in quantitative or qualitative terms. While all human activities carry some degree of risk, some risks are known with a relatively high degree of accuracy, because data have been collected on the historical occurrence of related problems (i.e. lung cancer caused by smoking, auto accidents caused by alcohol impairment, and fatalities resulting from airplane travel). For several reasons, risks associated with activities including exposure to chemicals such as pesticides cannot be so readily determined. The process of risk assessment helps evaluate the risks resulting from these situations.
When evaluating risks from the use of pesticides proposed in a NEPA planning document, reliance on U.S. EPA’s pesticide registration process as the sole demonstration of safety is insufficient. The Forest Service and Bureau of Land Management were involved in court cases in the early 1980’s that specifically addressed this question (principally Save Our Ecosystems v. Clark, 747 F.2d 1240, 1248 (9th Circuit, 1984) and Southern Oregon Citizens v. Clark, 720 F. 2d 1475, 1480 (9th Cir. 1983)). These court decisions and others affirmed that although the Forest Service can use U.S. EPA toxicology data, it is still required to do an independent assessment of the safety of pesticides rather than relying on FIFRA registration alone. The Courts have also found that FIFRA does not require the same examination of impacts that the Forest Service is required to undertake under NEPA. Further, Forest Service assessments consider data collected from both published scientific literature and data submitted to U.S. EPA to support FIFRA product registration, whereas U.S. EPA utilizes the latter data only. The U.S. EPA also considers many forestry pesticide uses to be minor. Thus, the project-specific application rates, spectrum of target and non-target organisms, and specialized exposure scenarios evaluated by the Forest Service are frequently not evaluated by U.S. EPA in its generalized registration assessments.
Risk assessment documents and worksheets have been developed for a number of pesticides that are used by the Forest Service. Existing risk assessments may be used in lieu of a project-specific risk assessment.
For further detail of the Forest Service risk assessment process for pesticides and how it is used, please consult “Preparation of Environmental Documentation and Risk Assessments”.
Risk Assessment Worksheets
Risk assessment worksheets are a computational tool developed for the USDA Forest Service by Syracuse Environmental Research Associates, Inc. (SERA). These worksheets perform many of the calculations used in the Human Health Risk Assessments (HHRA) and Ecological Risk Assessments (ERA) prepared for many of the pesticides used by the Forest Service.
Worksheet Use
The basic idea of these worksheets is to isolate the computations from the discussions of the computations. The worksheets contain very little discussion and they are intended as a tool to make risk assessment calculations easier to understand and review. Pesticide Coordinators and other technical specialist familiar with HHRAs and ERAs can use these worksheets to develop risk values for the pesticide application rates and application scenarios specific to their particular pesticide project. The worksheets for the pesticides listed below, are presented in EXCEL format and can be downloaded for your use. The worksheets can be used to perform computer based project specific (site-specific) calculations that incorporate the characteristics of your project including chemical formulation, use rate, and site factors.
Documentation
Prior to using the worksheets, we recommend that you read the documentation provided for WorksheetMaker Version 6.01.16 and the accomanying errata notes provided by SERA Inc. The documentation explains the organization of the worksheets, computation specifications, and other technical information. The latest release of WorksheetMaker Version 6.01.16 and supporting documentation, including the User Guide, is contained within the WorksheetMaker 6.01.16 zip file. This version includes the corrections to the WSM database from July 2016. See the documentation for additional details.
Support
Please note that SERA Inc. do not provide technical support for this product through telephone inquiries. If you have any questions about the worksheets, please contact the appropriate Regional Pesticide Coordinator in your region. For the pesticides Isoben, MCH and Verbenone, the worksheets available are in an earlier Version 2,04b, but will perform the same computations.
| HERBICIDES | DOCUMENTATION/WORKSHEET |
|---|---|
| Aminocyclopyrachlor | Aminocyclopyrachlor (1.8 MB PDF) Aminocyclopyrachlor EPA Bibliography (320 KB PDF) Worksheet (Attachment 1) (2.3 MB xlsm) Worksheet (Attachment 2) (1.7 MB xlsm) |
| Aminopyralid | Aminopyralid (1.38 MB PDF) Worksheet (5.5 MB xls) |
| 2,4-D | 2,4-D (1.4 MB PDF) Worksheet (Acid & Salt) (5.4 MB xls) Worksheet (Esters) (4.6 MB xls) |
| Chlorsulfuron | Chorsulfuron (941 KB PDF) Worksheet (5 MB xls) |
| Clethodim | Clethodim (2.5 MB PDF) Worksheet (Single Application) (2.4 MB xlsm) Worksheet (2 Applications) (2.4 MB xlsm) Worksheet (4 Applications) (2.4 MB xlsm) Worksheet (18 Applications) (2.4 MB xlsm) |
| Clopyralid | Clopyralid (940 KB PDF) Worksheet (5 MB xls) |
| Dicamba | Dicamba (Vanquish) (1 MB PDF) Worksheet (5 MB xls) |
| Endothall | Endothall (1.28 MB PDF) Worksheet (Aq K) (5.45 MB xls) Worksheet (Aq Super K) (5.4 MB xls) Worksheet (Liquid) (5.45 MB xls) Worksheet (Granular) (5.4 MB xls) Worksheet (Occup) (273 KB xls) |
| Fluazifop-P-Butyl | Fluazifop-P-Butyl (2.7 MB PDF) Worksheet (Single Application) (2.4 MB xlsm) Worksheet (2 Applications) (2.4 MB xlsm) Worksheet (3 Applications) (2.4 MB xlsm) |
| Fluridone | Fluridone (1.1 MB PDF) Worksheet (5 MB xls) |
| Fluroxypyr | Fluroxypyr (1.4 MB PDF) Worksheet (5.8 MB xls) |
| Glyphosate (Accord, Rodeo, Roundup, Roundup Pro) | Glyphosate (1.84 MB PDF) Glyphosate Appendices (1.3 MB PDF) Worksheet (Backpack) (6 MB xls) Worksheet (Ground) (6 MB xls) Worksheet (Aerial) (6 MB xls) Worksheet (Aquatic) (5.5 MB xls) Worksheet (Interactions) (245 KB xls) |
| Hexachlorobenzene | Worksheet (in Clopyralid) (4.8 MB xls) Worksheet (in Picloram) (4.8 MB xls) |
| Hexazinone | Hexazinone (1.3 MB PDF) Worksheet (granular) (5 MB xls) Worksheet (liquid) (5 MB xls) |
| Imazamox | Imazamox (1.3 MB PDF) Worksheet (Aquatic) (5.5 MB xls) Worksheet (Terrestrial) (6 MB xls) |
| Imazapic | Imazapic (602 KB PDF) Worksheet (5 MB xls) |
| Imazapyr (Arsenal, Chopper, Stalker) | Imazapyr (1.8 MB PDF) Worksheet (Aquatic) (1.9 MB xlsm) Worksheet (Terrestrial) (2.1 MB xlsm) |
| Isoxaben | Isoxaben (2.8 MB PDF) Worksheet (446 KB xls) |
| Metsulfuron Methyl (Escort) | Metsulfuron Methyl (928 KB PDF) Worksheet (5 MB xls) |
| Oryzalin | Oryzalin (536 KB pdf) Worksheet (2.3 MB xlsm) |
| Oxyfluorfen | Oxyfluorfen (1.16 MB PDF) Worksheet (5.6 MB xls) |
| Picloram | Picloram (2.37 MB PDF) Worksheet (5 MB xls) Worksheet (Foliar Applications) (2.13 MB xlsm) Worksheet (Hexachlorobenzene) (1.27 MB xlsm) |
| Sethoxydim (Poast) | Sethoxydim (Poast) (3 MB PDF) Worksheet (Poast) (379 KB xls) |
| Sulfometuron Methyl | Sulfometuron Methyl (876 KB PDF) Worksheet (5 MB xls) |
| Tebuthiuron | Tebuthiuron (1.9 MB PDF) Worksheet (Attachment 1) (2.3 MB xlsm) Worksheet (Attachment 2) (2.2 MB xlsm) Worksheet (Attachment 3) (2.2 MB xlsm) Worksheet (Attachment 4) (2.2 MB xlsm) |
| Trifluralin | Trifluralin (2.16 MB PDF)
Worksheet (Attachment 1) (2.1 MB xlsm) |
| FUNGICIDES | DOCUMENTATION/WORKSHEET |
| Borax | Borax (1.8 MB PDF) Worksheet (cellu-treat) (1.7 MB xlsm) Worksheet (liquid) (1.7 MB xlsm) Worksheet (dry-stump) (1.7 MB xlsm) |
| Chlorothalonil | Chlorothalonil (436 KB pdf) Worksheet (2.3 MB xlsm) |
| Dazomet | Dazomet (345 KB pdf) Worksheet (1.9 MB xlsm) |
| Mancozeb | Mancozeb (454 KB pdf) Worksheet (2.3 MB xlsm) |
| INSECTICIDES | DOCUMENTATION/WORKSHEET |
| Carbaryl | Carbaryl (1.72 MB PDF) Worksheet (bark beetle) (5 MB xls) Worksheet (leaf beetle) (5 MB xls) |
| Chlopyrifos | Chlopyrifos (346 KB pdf) Worksheet (2.3 MB xlsm) |
| DDVP | DDVP (Dichlorvos) (1.4 MB PDF) Worksheet (248 KB xls) |
| Diflubenzuron | Diflubenzuron (Dimilin) (1.15 MB PDF) Worksheet (5 MB xls) |
| Dinotefuran | Dinotefuran (1.63 MB PDF) Worksheet (ABF 1) (5.8 MB xls) Worksheet (ABF 2) (5.8 MB xls) Worksheet (granular) (5.7 MB xls) Worksheet (bark) (5.7 MB xls) Worksheet (soil) (5.4 MB xls) Worksheet (tree) (5 MB xls) Worksheet (bees) (194 KB xls) |
| Emamectin Benzoate | Emamectin Benzoate (1.4 MB PDF) Worksheet (1 MB xlsm) |
| Gypchek | Gypchek (414 KB PDF) |
| Imidacloprid | Imidacloprid (3 MB PDF) Imidacloprid Appendices (1.4 MB PDF) Worksheet (tree-injection) (1.6 MB xlsm) Worksheet (soil-injection) (2 MB xlsm) Worksheet (bark-applications) (2.3 MB xlsm) Worksheet (backpack-directed-foliar) (2.3 MB xlsm) |
| Lambda-Cyhalothrin | Lambda-Cyhalothrin (1.54 MB PDF) Worksheet (Chico) (6.05 MB xls) Worksheet (Foresthill) (6.03 MB xls) |
| Malathion | Malathion (1.93 MB PDF) Worksheet (ULV) (5.19 MB xls) Worksheet (EC) (5.18 MB xls) |
| Rotenone | Rotenone (1.64 MB PDF) Worksheet (5 MB xls) |
| Spinosad | Spinosad (2.5 MB PDF) Worksheet (one application) (2.4 MB xlsm) Worksheet (two applications) (2.4 MB xlsm) |
| Tebufenozide (Mimic) | Tebufenozide (Mimic) (884 KB PDF) Worksheet (granular) (5 MB xls) |
| PHEROMONES | DOCUMENTATION/WORKSHEET |
| Disparlure | Disparlure (413 KB PDF) Worksheet (167 KB xls) |
| Methylcyclohexene-1-one (MCH) | Methylcyclohexene-1-one (MCH) (267 KB PDF) Worksheet (154 KB xls) |
| Verbenone | Verbenone (240 KB PDF) Worksheet (157 KB xls) |
| OTHER RISK ASSESSMENTS/WORKSHEETS | DOCUMENTATION/WORKSHEET |
| An Evaluation of Gleams-Driver for Estimating Concentrations of Pesticides in Surface Water | An Evaluation of Gleams-Driver for Estimating Concentrations of Pesticides in Surface Water (851 KB PDF) |
| Aqueous Chlorine-Based Antimicrobial/Disinfectant | Aqueous Chlorine-Based Antimicrobial/Disinfectant (999 KB PDF) |
| Chlorophacinone | CHLOROPHACINONE (1.15 MB PDF) Worksheet (2 MB xlsm) |
| Gypsy Moth Risk Comparison | Gypsy Moth Risk Comparison (570 KB PDF) |
| Marker Dyes | Marker Dyes (204 KB PDF) |
| Neurotoxicity, Immunotoxicity, and Endocrine Disruption with Specific Commentary on Glyphosate, Triclopyr, and Hexazinone | Neurotoxicity, Immunotoxicity, and Endocrine Disruption with Specific Commentary on Glyphosate, Triclopyr, and Hexazinone (251 KB PDF) |
| Preparation of Environmental documentation and Risk Assessments | Preparation of Environmental documentation and Risk Assessments (1.8 MB PDF) |
| Strychnine | Strychnine (2.46 MB PDF) Worksheet (5.83 MB xls) |
| Surfactants Effects on Glyphosate Toxicity | Surfactants Effects on Glyphosate Toxicity (149 KB PDF) |
| Technical Comparison of EPA, BLM and Forest Service Pesticide Risk Assessments | Technical Comparison of EPA, BLM and Forest Service Pesticide Risk Assessments (198 KB PDF) |
| Tussock Moth Biocontrol Toxicity | Tussock Moth Biocontrol Toxicity (198 KB PDF) |
| Worker Exposure 2014 | Worker Exposure 2014 (1.75 MB PDF) Worker Exposure 2014 Appendices (771 KB PDF) Worksheet (918 KB xlsm) |