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Environmental Impact Quotient (EIQ) Explained

There is a wealth of toxicological and environmental impact data for most pesticides that are used in agriculture and horticulture, largely because of the pesticide registration process. However, these data are not all readily available or organized in a manner that is usable to the IPM practitioner.

A method called the Environmental Impact Quotient (EIQ)  was devised to determine the environmental impact of most commonly used pesticides (insecticides, fungicides, and herbicides) in agriculture and horticulture. The values obtained from these calculations can be used to compare the environmental impact of different pesticides and pest management programs. The EIQ provides criteria to be used along with the pest manager’s knowledge of efficacy, cost and resistance management to select a pesticide product when deemed necessary. (See A Method to Measure the Environmental Impact of Pesticides at the NYSIPM Program website.)

The EIQ is based on data obtained from EXTOXNET, the Cornell Pesticide Management Education Program, SELCTV database, the National Pesticide Information Center (developed by the USDA Agricultural Research Service and Soil Conservation Service), Material Safety Data Sheets (MSDS), EPA factsheets and databases, the Pesticide Properties Database, and technical bulletins developed by the agricultural chemical industry.

Factors such as toxicity (dermal, bird, chronic, bee, fish, beneficial arthropod), soil half-life, systemicity, leaching potential, plant surface half-life, surface loss potential, and farm worker, consumer, and ecological effects are all considered when calculating an EIQ for a particular pesticide. The result is a single number describing the EIQ of a pesticide active ingredient. The New York State Food and Life Sciences Bulletin No. 139 entitled “A Method to Measure the Environmental Impact of Pesticides” describes in detail the derivation of the EIQ. The full content of the bulletin is available at the website cited above, along with an updated table of EIQ values, including those for many active ingredients that have come on the market in the nearly two decades since the model was originally developed. Although the model was developed for food crops, the “farm worker” component can be considered equivalent to the effects to turfgrass applicators and the “consumer” component to the turfgrass user, e.g. golfer, athlete, child. An extended explanation of the EIQ model  can be viewed in video format.

Once an EIQ value has been established for the active ingredient of a pesticide, EIQ field use ratings (EIQ-FUR) can be calculated. To compare pesticides and pest management strategies, the dose, the formulation or percent active ingredient of the product, and the frequency of application of each pesticide needs to be considered. The EIQ-FUR was developed to account for different formulations of the same active ingredient and different use patterns. This rating is calculated by multiplying the EIQ value for the specific chemical by the percent active ingredient in the formulation and by the rate used, usually in pints or pounds of formulated product per acre.

EIQ Field Use Rating (EIQ FUR) = EIQ x % Active Ingredient x Rate

Table 1: Example of the EIQ Field Use Rating for five fungicides targeting dollar spot.
Material Active Ingredient EIQ % Active Ingredient Rate EIQ Field Use Rating
Daconil Ultrex Turf Care chlorothalonil 37.4 82.5 3.7 oz/1000 ft2

(10.07 lb/acre)

*NY3336F thiophanate methyl 23.8 41.25 2 fl. oz./1,000 ft2

(5.44 pints/acre)

Bayleton 50% WSP triadimefon 27 50 1 oz./1,000 ft2

(2.72 lb/acre)

Banner Maxx propiconazole 31.6 14.3 1 oz./1,000 ft2

(2.72 pints/acre)

Roots EcoGuard Biofungicide Bacillus licheniformis 7.3 0.14 20 fl. oz./1,000 ft2

(54.45 pints/acre)


The lower the EIQ-FUR, the lower the environmental impact. This method allows comparisons of the environmental impact among pesticides and different pest management programs. Pesticides should be compared based on the EIQ-FUR of the product only, not by the base EIQ of the active ingredient. As an example, if several pesticides are registered against a particular pest, which pesticide has the least impact on the environment? Table 1 shows a comparison of the environmental impact of five turfgrass fungicides.

In this example, the EIQ Field Use Ratings have been calculated for five fungicides registered for dollar spot control, at the low curative rate. Note that although thiophanate-methyl has a lower base EIQ (23.8) than most of the other active ingredients listed, it has the second highest EIQ-FUR. The Field Use Rating is dependent on the %AI and the rate of application. Also be aware that small differences in the EIQ-FUR are not meaningful, rather the relative level and ranking are. The following can be used as a guide for turfgrass managers:

EIQ Field Use Rating
<25 very low
<50 low
50-100 moderate
>100 high
>150 very high

The products listed in this example differ in efficacy, mode of action (coded by FRAC/IRAC/WSSA in table 9), potential for causing resistance, and cost–as well as EIQ-FUR. A turfgrass manager should consider all of these differences when selecting a pesticide and an overall management strategy. The addition of a measure of environmental impact enhances the professional’s ability to make well-informed choices.

The EIQ Field Use Rating can be used to compare different pest management strategies, and to compare seasonal totals from year to year. To do so, calculate the EIQ-FUR for each application made or planned for the season and simply sum them up. By using the EIQ model, it becomes possible for IPM practitioners to easily estimate the environmental impact of different pesticides combinations and choices.

EIQ Calculator makes it easy

A new tool was recently added to the NYS IPM Program website, the EIQ Calculator. It makes EIQ calculations easy, regardless of the units of weight, volume or area being used. The calculator also references the most current base EIQ values in determining EIQ-FURs. Try it out at and find out the environmental impact of your management on the properties you take care of.

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