How does it work?

1. What is the purpose of the Environmental Yardstick for municipalities, businesses and citizens?

The Environmental Yardstick for Pesticide is a tool to find out how harmful different pesticides are for the environment. The Environmental Yardstick measures the environmental impact of pecticides applied on both paved as well as unpaved terrain.

In the case of paved terrain, the Environmental Yardstick calculates and compares the effects of herbicides on three criteria:

risks for leaching to groundwater
risks for aquatic organisms in surface waters
risks for the applicator of the pesticide

In the case of unpaved terrain, the Environmental Yardstick calculates and compares the effects of pesticides on five criteria:

risks for leaching to groundwater
risks for aquatic organisms in surface waters
risks for soil organisms
risks for beneficial organisms such as biological controllers and pollinators
risks for the applicator of the pesticide

2. Which score of environmental impact points (EIP) is acceptable?

The environmental effects of pesticides on aquatic organisms, soil organisms and groundwater are expressed in Environmental Impact Points (EIP). The higher the EIP score, the higher the risk for the environment. EIP scores are defined for a dose of 1 l/ha or 1 kg/ha, and need to be multiplied with the amount of pesticide used per hectare. A score of 100 EIP is equivalent to the maximum acceptable level as defined by the Board for the Authorisation of Plant Protection Products and Biocides (CTGB). The maximum acceptable level is a concentration at which the pesticide poses an acceptable risk to the environment.

3. How are environmental impact points (EIP) for groundwater calculated?

In the case of paved terrain, the environmental impact for groundwater is caused by the part of the herbicide that leaches to the groundwater, and is dependent on the chemical properties (reaction with soil particles), the dosage and the type of pavement.

The soil organic matter content often appears to be determining in the risk of leaching to groundwater, because soil organic matter is capable of retaining pesticides. Due to the sandy soils that are typically used as pavement substrate, the Environmental Yardstick assumes a soil organic matter percentage of < 1.5%.

In the case of unpaved terrain the soil organic matter content also appears to be determining in the risk of leaching to groundwater. Ofcourse are the chemical properties of pesticides are also important in determining the extent of leaching.

Additonally, the EIP score for groundwater depends on the season of application. Application in the period of september until februari produces a larger risk of leaching is than application in the period of march until august. The higher risk of leaching in the first period is caused by a slower rate of degradation due to lower ambient temperatures, and generally a higher precipitation surplus. In assigning environmental impact points a distinction is made between the following periods:

1 March- 31 August
1 September - 29 February

Ofcourse these boundaries are not as distinct in reality, and leaching as a result of appliction on the 31st of August will not differ greatly form leaching as a result of application on the 1st of September. The purpose of the distinction between these two periods is to emphasise the difference in leaching rates during the year. However, when the pesticide label mentions a date, this date should be taken as distinct limit.

4. How are environmental impact points (EIP) for aquatic organisms calculated?

For paved surfaces the environmental impact for aquatic organisms is caused by the fraction of pesticide runoff. The enviromental impact depends on the amount of pesticide used, the treated surface, the chemical properties of the pesticide (toxicity for aquatic organisms), the type of pavement and the presence of sewage watercourses and surface water bodies.

For unpaved surfaces, the environmental impact for aquatic organisms depends on the toxicity of the pesticide for aquatic organisms and the presence of surface water bodies.

5. How are environmental impact points (EIP) for soil organisms calculated?

The Environmental Yardstick includes the organic matter content in the soil when determining the EIP score. Together with the chemical properties of the pesticide, the organic matter content is determining for the amount of pesticide that remains present in the soil. This concentration, combined with the toxicity, determines the risk the pesticide poses for soil organisms.

The environmental yardstick discerns 5 classes of organic matter content:

lower than 1,5 % percent organic matter
1,5 - 3 %
3 - 6 %
6 - 12 %
more than 12 %

To each of the classes environmental impact points for soil organisms are assigned. For gardens and parks a organic matter content of 3-6 % is common.

6. How are the risks for the pesticide applicator displayed?

The risks for the pesticide applicator are displayed using symbols. These symbols are based on the symbols (e.g. skull and crossbones, saltire) typically found on the pesticide label.

7. Which environmental impacts are most important?

Pesticides recieve scores on seperate criteria. A user (grower, gardener, municipality, citizen) may then decide which impact is most important. If a region where alot of open watercourses of surface water bodies are present, the risk to aquatic organisms may be more important. For a user in a groundwater protection zone, the risk to groundwater may be more important.

8. What sources are the Environmental Yardstick data based on?

Data in the environmental yardstick are based on De gegevens in de Milieumeetlat zijn afkomstig van de volgende bronnen:

EIP aquatic organisms: CTGB (calculation by CLM)
EIP soil organisms: CTGB (calculation by CLM)
EIP groundwater: CTGB (calculation by CLM)
Beneficial organisms: Side effect database by Koppert Biological Systems
Applicator safety: Pesticide database by NVWA