Imazapyr (128821) 

Screening Level Usage Analysis (SLUA) 

Date: April 29, 2013 

What is a Screening Level Usage Analysis (SLUA)? 

 Available estimates of pesticide usage data for a particular active ingredient that is used on 

agricultural crops in the United States.

 Pesticide usage data obtained from various sources. The data are then merged, averaged, and 

rounded so that the presented information is not proprietary, business confidential, or trade secret. 

What does it contain? 

 Pesticide usage data for a single active ingredient only.

 Agricultural use sites (crops) that the pesticide is reported to be used on. 

 Available pesticide usage information from U.S. states that produce 80% or more of a crop, in most 

cases, or less than 80%, in rare cases, depending on the scope of the survey and available resources.

 Annual percent of crop treated (average & maximum) for each agricultural crop.

 Average annual pounds of the pesticide applied for each agricultural crop (i.e., for the states 

surveyed, not for the entire United States). 

What assumptions can I make about the reported data? 

 Average pounds of active ingredient applied - Values are calculated by merging pesticide usage 

data sources together; averaging across all observations, then rounding. Note: If the estimated value 

is less than 500, then that value is labeled <500. Estimated values between 500 & <1,000,000 are 

rounded to 1 significant digit. Estimated values of 1,000,000 or greater are rounded to 2 significant 

digits.) 

 Average percent of crop treated - Values are calculated by merging data sources together; 

averaging by year, averaging across all years, & rounding to the nearest multiple of 5. Note: If the 

estimated value is less than 2.5, then the value is labeled <2.5. If the estimated value is less than 1, 

then the value is labeled <1. 

 Maximum percent of crop treated - Value is the single maximum value reported across all data 

sources, across all years, & rounded up to the nearest multiple of 5. Note: If the estimated value is 

less than 2.5, then the value is labeled <2.5.

What are the data sources used? 

 USDA-NASS (United States Department of Agriculture’s National Agricultural Statistics Service) – 

pesticide usage data from 2004 to 2011. 

 Private pesticide market research – pesticide usage data from 2004 to 2011.

 California Department of Pesticide Regulation (DPR) Pesticide Use Reporting (PUR) data for 

2004 to 2010. 

What are the limitations to the data? 

 Additional registered uses may exist but are not included because the available surveys do not report 

usage (e.g., small acreage crops). 

 Lack of reported usage data for the pesticide on a crop does not imply zero usage. 

 Usage data on a particular site may be noted in data sources, but not quantified. In these instances, 

the site would not be reported in the SLUA. 

 Non-agricultural use sites (e.g., turf, post-harvest, mosquito control, etc.) are not reported in the 

SLUA. A separate request must be made to receive these estimates. 

 Some sites show some use, even though they are not on the label. This usage could be due to 

various factors, including, but not limited to Section 18 requests, existing stocks of the chemical, 

data collection errors, and experimental use permits (EUPs). 
 

Date: April 29, 2013 

Screening Level Estimates of Agricultural Uses of Imazapyr (128821) 

Sorted Alphabetically

Reporting Years: 2004-2011 

Percent Crop Treated 

Crop Lbs. A.I. Avg. Max. 

1 Corn 9,000 <1 <2.5 

2 Pasture 2,000 <1 <2.5 

All numbers are rounded. 

 <2.5: indicates less than 2.5 percent of crop is treated. 

 <1: indicates less than 1 percent of crop is treated. 

SLUA data sources include: 

USDA-NASS (United States Department of Agriculture's National Agricultural Statistics Service) 

Private Pesticide Market Research 

These results reflect amalgamated data developed by the Agency and are releasable to the public.