Appendix 3: Climate- sensitive parameters: detailed evaluation of regulatory sections

OECD Guideline 307 (aerobic) (2002)

Laboratory
DT50 in aerobic soil
Metabolite determi­nation

Aerobic soil: temperature, moisture, organic carbon content, texture

20 ± 2

at a pF of between 2.0 and 2.5

carried out in the dark

Considerations: tests are performed under artificial / optimised conditions and degradation parameters are normalised for modelling --> thus an adjustment of test parameters is maybe not necessary (to be considered that biodegradation studies are performed at 12 °C under REACH)
Possible effects of climate change on study performance: in case of more droughts or flooding, soil sampling could become more challenging. Questions: How fast can the microbial communities recover after a drought? Should there be a guidance to interpret the results after extreme weather conditions as they are expected to increase?
Are additional tests needed to get more precise information to predict degradation under field conditions? How significantly are soil parameters generally affected by climate change:  changes in microbial communities? Effects on organic carbon content and other parameters? Effects on non-extractable residues (NER) formation/degradation?

yes

OECD Guideline 307 (anaerobic) (2002)

Laboratory, DT50 in anaerobic soil
Metabolite determination

Aerobic/​anaerobic soil: temperature, moisture, organic carbon content, texture

20 ± 2

at a pF of between 2.0 and 2.5 / flooded

carried out in the dark

Can anaerobic conditions become more or less relevant for registration? More precipitation? More droughts?

yes

OECD draft guideline (soil photolysis) (2002)

Laboratory,
DT50 soil photolysis, Metabolite determination

temperature, moisture, organic carbon content, texture

20 ± 2

75% of field capacity / air dried

Samples irradiated under conditions simulating natural sunlight

Are there more sunny days expected in some areas which could affect the potential for soil photolysis under natural conditions?
Effect of moisture on photolysis rate?

yes

OECD Series on Pesticides and Biocides No 82. (Terrestrial Field Dissipation) (2016)

Field study
DT50 /DegT50 field soil for parent and metabolites, if possible

Soil moisture, soil temperature, organic carbon content, texture

natural conditions

natural conditions

natural sunlight

Changes in temperature and moisture directly influence the rate of dissipation and metabolite formation.
Furthermore, effect of droughts and floods are expected, the risk for invalid trials can increase, for example flooding could ruin a field trial site. Leaching can be enhanced at higher precipitation rates than usual or if substance bound to organic carbon content is released again.
Possible adjustments: more trials to be investigated to cover risks? Investigations needed to ensure microbial activity? Influence on irrigation scheme?

yes

OECD Guideline 106 (adsorption/​desorption) (2000)

Laboratory
adsorption /desorption parameters in soil

temperature, pH, organic carbon content, soil texture

20 ± 2

soil/water slurry

carried out in the dark

Considerations: tests are performed under artificial / optimised conditions and parameters are normalised for modelling --> thus an adjustment of test parameters is maybe not necessary
--> however, adsorption is also influenced by temperature / organic carbon content / pH and minerals

yes

Scientific Opinion on aged sorption (2018)

Laboratory,
Aged sorption parameters

temperature, pH, organic carbon content, soil texture

20 ± 2

soil/water slurry

carried out in the dark

 

yes

OECD Guideline 312 (leaching in soil columns) (2004)

Laboratory
Mobility in soil columns

temperature, pH, organic carbon content, soil texture

18–25 °C

saturated conditions

carried out in the dark

 

yes

OECD Series on Testing and Assessment No. 22 (Lysimeter studies) (2000)

Semi-Field
Leaching behaviour

precipitation, temperature, pH, organic carbon content, soil texture

natural conditions

unsaturated/
saturated

natural  sunlight at the top

Similar considerations as for TFD studies - however, the studies are only performed in rare cases

yes

OECD Guideline 111 (hydrolysis) (2004)

Hydrolysis at pH 4,7, 9 at 50 °C (and potentially 2 further temperatures

temperature and pH, sterile buffer solutions at 2 pH values

50 °C and 2 additional temperatures

 -

carried out in the dark

The hydrolytic and photolytic behaviour is investigated under artificial conditions --> no adjustment is considered necessary

no

OECD Guideline 316 (direct photolysis) (2023)

Photolysis in sterile buffer

temperature, pH, sterile conditions

 23 to 27 °C (25 ± 2) °C

 -

Samples irradiated under conditions simulating natural sunlight / dark control

The hydrolytic and photolytic behaviour is investigated under artificial conditions --> no adjustment is considered necessary

no

OECD Guideline 316 (indirect photolysis) (2023)

Photolysis in natural water

temperature, pH

 23 to 27 °C (25 ± 2) °C

 

Samples irradiated under conditions simulating natural sunlight

Considerations:
tests are performed under artificial / optimised conditions and parameters are normalised for modelling --> thus an adjustment of test parameters is maybe not necessary (to be considered --> some studies for REACH are performed at 12 °C)
The following adjustments could be helpful: when can sampling be done after droughts or flooding to ensure representative microbially active water bodies?
Possible effects of climate change: How are water microorganism / particles / oxygen content and pH influenced by a changed temperature and changed precipitation or extreme events? How significant are the effects of droughts or rainfall events on particles / algae or microbial communities in the water? --> Changes could lead to different water parameters, more details for sampling times might be needed.

yes

OECD Guideline 309 (aerobic mineralisation in surface water) (2004)

DT50 in aerobic surface water

temperature, pH, oxygen concentration, redox potential

20 ± 2

 

carried out in the dark

yes

OECD Guideline 308 (aerobic degradation in water/sediment) (2002)

Degradation in water/​sediment systems

temperature, pH, oxygen concentration, redox potential

20 ± 2

 

carried out in the dark

yes

OECD Guideline 308 (irradiated aerobic degradation in water/sediment) (2002)

Degradation in water/​sediment systems under irradiated conditions

temperature, pH, oxygen concentration, redox potential

20 ± 2

 

Samples irradiated under conditions simulating natural sunlight

yes

OECD Guideline 301 (ready biodegradability) (1992)

Biodegra​dability

 

 

 

 

 

yes

Guidance document on the impact of water treatment processes (2023)

Potential Residues in drinking water

 

 

 

 

 

yes

Atkinson approach (calculation of photodegradation in air)

DT50 Air

 

 

 

 

 

yes

OECD Guideline 104 (vapour pressure) (2006)

Vapour pressure

 

 

 

 

 

yes

Transport via air

Assessment based on available data

 

 

 

 

 

yes

Overall Residue definition

Decline of parent and formation of metabolites in soil, water/​sediment and groundwater

 

 

 

 

Increased temperatures could lead to a higher degradation of parent and higher amounts of metabolites, general changes in microbial communities or organic carbon contents could also have an effect on the degradation potential in soil

yes

Defined FOCUS crops for GW/SW

 

To be checked if new major crops are expected to emerge on the (Northern) European market and if they would need to be implemented as FOCUS crops
See DEPA report…e.g. Grain maize and some new protein and oil seed crops

yes

FOCUS crop distribution

 

Is the distribution of the crops as provided in FOCUS reports still up to date? Or was / will a major shift in crop regions take place? Do some (SEU/CEU) FOCUS crop need to be parameterised for NEU scenarios (e.g. maize)?

yes

Extension of GW/SW-Scenarios in EU/NEU

 

Are the current GW and SW FOCUS scenarios still appropriate? Is it sufficient to update the weather files or would it be more suitable to adopt the concept on a larger frame?
Do countries need to overthink "their" relevant scenarios?

yes

Drift curves

 

Are the Rautmann drift values still up to date even under changing climatic conditions? New values would be needed for further management/application techniques.

potentially

Model parameter/variable

Air temperature

Air temperature affects soil temperature, which in turn impacts soil moisture, organic matter decomposition, evaporation, and pesticide degradation

yes

Model parameter/variable

Precipitation

Climate change can lead to changes in the amount, intensity, and distribution of precipitation. This can result in more frequent or intense rainfall events or prolonged dry periods. Changes in precipitation can impact soil moisture dynamics, runoff patterns, and the frequency and intensity of erosion events. This can affect the model's predictions of water movement and pesticide leaching.

yes

Model parameter/variable

Solar radiation

Solar radiation drives the evapotranspiration process, which is crucial for modelling soil moisture and water movement. Radiation in the atmosphere might change with changing composition (e.g. H₂O and CO₂ content). However, impact expected to be low.

no / indirectly sensitive

Model parameter/variable

Light day hours

Not directly affected by climate change. It is primarily determined by the Earth’s orbital parameters and axial tilt. Day length influences the amount of solar energy available for evapotranspiration. ==> no changes expected

no

Model parameter/variable

Humidity

Humidity affects the rate of evapotranspiration from soil and plants.

yes

Model parameter/variable

Wind speed 

 

no / indirectly sensitive

 

Dates of time series

Changes in weather data need to be considered and be updated on a regular basis:
1) Update to new time series based on recent data from MARS or local weather station. Update in regular (5-10 years) intervals. ==> better than current approach, however, still has the flaw that it only uses data from the past and is potentially still depending on single major events at specific dates
2) Implementation of scenarios/predictions/uncertainties of climate modelling ==> would make use of climate predictions for the future. Would need a major overhaul of the current status and potentially much more computing power.
3) A combination of both: Use recent (past) weather data and scale it up with climate predictions (e.g. temperature and rainfall factor, increased drought periods, extreme rainfalls...)

yes

 

Length of time steps

Currently the time steps of the weather data are 1 day. However, especially run-off and drainage events are driven by rainstorms which are sub-daily (if not sub-hourly). It would be important to cover these strong short-term rainfalls appropriately in the weather data. Some models like MACRO and PEARL can handle sub-daily rainfall, while e.g. PRZM cannot.

yes

AppDate / BBCH stages for FOCUS crops / Emergence and Harvest dates for NEU GW scenarios

 

Application dates are usually defined by BBCH stages. Relationship is described in AppDate for FOCUS scenarios and the most relevant crops. These relationships might need to be reviewed.
Second season crops in NEU?
Additionally a more flexible approach could be envisaged e.g. using the temperature sum model (as e.g. implemented in FROGS). With this model BBCH stages could be "predicted" more flexible with changing weather time series.

yes

PELMO

 

Models might need to be updated to be able to deal with extreme conditions, especially for short term rainfall events (sub daily or even sub-hourly). Usage of some models to be re-evaluated, since some models might not be adaptable.

yes

PEARL

 

 

MACRO

 

 

SWASH (SPIN, PRZM, TOXSWA, MACRO)

 

 

STEPS 1-2

 

Re-evaluation might be necessary to check if the percentages and assumption of drift/runoff/drainage, discharge volumes are still conservative

maybe

SWAN

 

Are the percentages for runoff/erosion reduction still appropriate? Or are more sophisticated models like VFSmod required? Consideration of runoff in NEU?

maybe

Nordic PECsoil calculator

 

Temperature in Finnish scenario

yes

PERSAM

 

Future model under discussion. OC content under discussion and climatic files potentially similarly impacted as in PEARL/PELMO

 

Model parameter/variable

Tillage

Potentially new farming practices are becoming more important e.g. to avoid erosion etc. No tillage and reduced tillage ==> might have impact on OC content

maybe

Model parameter/variable

Irrigation

To be evaluated weather irrigation as included in FOCUS needs to be adapted for crops/scenarios based on changing farmers practice and longer drought periods

yes

Model parameter/variable

Soil temperature

Calculated by models based on air temperature

no

Model parameter/variable

Soil water content

Calculated by models based on precipitation/irrigation

no / indirectly sensitive

Model parameter/variable

Field capacity

Soil Water Retention Curve might be impacted by changes in organic carbon content.

maybe

Model parameter/variable

Wilting point

The wilting point itself is not directly sensitive to climate change as it is a property of the soil that remains relatively stable under different climatic conditions.

no

Model parameter/variable

Surface roughness (Manning in PRZM)

Climate change can influence surface roughness through changes in land use, vegetation cover, erosion rates, and precipitation patterns. For ex., more intense or frequent rainfall can lead to increased erosion, changing surface roughness. Changes in vegetation due to altered growing conditions or land management practices can also affect surface roughness.
Used in PRZM for erosion calculations (relevant for strongly compounds) and could also affect the performance of the filter strips. Depending on crop / crop stage. But currently it seems that this is not time dependent in FOCUS.
==> would need to be reviewed for SWASH and SWAN

no / indirectly sensitive

Model parameter/variable

organic matter content

Organic matter content may change over time which climate change. However, it is expected that changes take place over longer periods than the envisaged 10–25 years). Literature research and comparison of new/old database versions could give an indication of changes. Impact on PECs potentially large.

maybe

Model parameter/variable

Sand/Silt/Clay content

Indirectly sensitive: due to for ex. Erosion

no / indirectly sensitive

Model parameter/variable

Bulk density

Changes maybe in accordance with OC and management practices.
Abundance of earth worms may affect the soil structure.

no / indirectly sensitive

Model parameter/variable

soil pH

Soil pH may change over time with climate change. However, it is expected that changes take place over longer periods than the envisaged 10–25 years). Literature research and comparison of new/old database versions could give an indication of changes. Impact on PECs potentially small.
==> review relevant pH values for NEU countries
==> relevance of PEC calculations for substances with pH-dependency might change

maybe

Model parameter/variable

Ground water depth/bottom boundary

Ground water depth may change depending on precipitation and temperature. Impact on PEC-values is unclear. Sensitivity analysis could be done to evaluate if a major impact on pesticide risk assessment is expected
==> to be evaluated in which models this is relevant

yes

Model parameter

van Genuchten parameter

Would need to be adjusted in case new soil profiles are implemented

indirectly sensitive

Model parameter/variable

Transpiration rate/​Evapo­transpiration rate (ET)

The key factors affecting ET in response to climate change include: temperature, precipitation, humidity & solar radiation

indirectly sensitive

Model parameter/variable

Emergence Date

Shifts in temperature and precipitation can alter when crops emerge, affecting growth and productivity and harvest date ==> see above for Application Dates; relevant for FOCUS scenarios and also NEU-specific GW scenarios

yes

Model parameter/variable

Harvest Date

yes

Model parameter/variable

Leaf Area Index (LAI)

Variations in temperature and precipitation influence LAI, which in turn affects plant growth and productivity. Impact on PEC calculations expected to be small (see section 4.2.2.6).

yes

Model parameter/variable

Crop Factor

Crop factor modifies the standard reference potential evapotranspiration (PET) into PET for the simulated crop. Variations in temperature and precipitation influence Kc. Impact on PEC calculations expected to be small (see section 4.2.2.6).

yes

Model parameter/variable

Rooting depth

Temperatures can influence root growth rates and depths, changes in precipitation affect soil moisture levels, which can influence root development. Impact on PEC calculations expected to be small (see section 4.2.2.6).

yes

Aquatic organism testing: 

OECD Guideline 203 (2019)

Fish (acute)

Water: Oxygen content, pH, hardness, salinity etc.

water temp 21–25 °C species specific

Lux 540–1000 species specific and
intensity 10–20 µE m² s^-1

yes

OECD Guideline 211 (2011)

Aquatic invertebrates (Daphnia reproduction)

Water: Oxygen content, pH hardness, salinity etc.

water temp 18–22 °C

Lux 1000–1500 and intensity 15–20 µE m² s^-1

yes

OECD Guideline 239 (2014)

Aquatic plants (Myriophyllum, rooted macrophyte)

Water and sediment characteristics; pH between 7.5 - 8.0 for water media, peat/clay/sand content of sediment + nutrient medium.

water temp 20 ± 2 °C

wavelength 400–700 nm at water surface and intensity 140 +/- 20  µE m² s^-2

yes

Soil organism testing: 

OECD Guideline 222 (2016)

Earthworm reproduction

Artificial soil composition; OMC, clay, calcium carbonate, sand etc.

ambient air temp 20±2 °C

Lux 400–800

yes

OECD Guideline 216 (2000)

Soil micro-organisms

Natural soil composition; OMC, sand content, pH, microbial biomass, water holding capacity, moisture content     (40-60%)

ambient air temp 20 ± 2 °C

carried out in the dark

yes

Terrestrial organism testing: 

OECD Guideline 223 (2016)

Avian (acute oral)

-

ambient air temp 15–27 °C

photoperiod 8hrs light : 16hrs dark

yes

OECD Guideline 213 (1998)

Pollinators (Honeybee acute oral)

-

ambient air temp 25 ± 2 °C and    50–70% humidity

carried out in the dark

yes

IOBC - SETAC

NTA - Aphidius extended lab

suitable plant for fecundity phase

ambient air temp  20 ± 3 °C and 50–90% RH

400–3000 Lux for mortality phase
4000–20 000 Lux for fecundity phase

yes

OECD 227 Guideline (2006)

Terrestrial plants: vegetative vigour

Artificial soil composition; OMC, clay, sand etc.

ambient air temp 22 ± 10 °C and humidity 70% ± 25%

wavelength 400–700 nm  and  intensity 350 +/- 50  µE m² s^-2

yes

Considerations regarding ecotox risk assessment

Ecotox testing involves measurement of survival, rate of reproduction, biomass, weight etc., to determine endpoints for use in the risk assessments; EC50,20,10, NOEC .

maybe

Impact of climate changes on biodiversity

yes

Potential change in species sensitivity

maybe

Risk assessment: NEU specific avian species to consider at specific BBCH growth stages of crop (Willow warbler etc.). Flowering stages of crop specific to bee exposure.

maybe

Short cut values used in the avian and mammal assessments (EFSA GD). 

maybe

Potential change in PECsoil and PECsw values.

yes

Toxicology

 

 

no climate sensitive parameters were identified

 

EFSA online calculator (https://r4eu.efsa.europa.eu/).

 

 

no climate sensitive parameters were identified
However pay attention that some changes may appear due to climate change: Outcomes of DFR or exposure studies might be influenced by climate parameters and bridging approaches between zones might change. 

 

Relevance assessment of metabolites in groundwater

 

 

Indirectly affected by PECgw calculations. Further tox studies are potentially  needed but still covered by current method

No changes, covered by current method

Phys/Chem

 

 

no (not relevant for risk assessment)

 

Analytical methods

 

 

no climate sensitive methods are used; therefore no changes are required

 

Storage stability

 

 

Testing of shelf-life is dependent on ambient temperature which is defined for moderate/temperate, hot, and very hot climate. Potentially for some regions a shift to hotter climates for this test would need to be considered.

Review by member states

Metabolism in plants and animals

 

 

no climate sensitive methods are used; therefore no changes are required
However pay attention that metabolism can be influenced by the temperatures/CO2/stress in plants (Zandalinas S. et al., JEB, 2022) and may lead to additional metabolites or a shift in the relevant metabolites for the residue definition

 

Residues in plants

 

 

no climate sensitive methods are used; therefore no changes are required
However pay attention that some changes may appear due to climate change: shift of the geographical zones for residue trials, change of typical crops growing areas, change of major/minor crops status in northern zone

 

MRL calculator

 

Mean/SD

no
However due to more extreme conditions (drought/flooding, higher temperatures, local thunderstorm, plant stress), a higher variance in local plant growth and herewith residues levels within the northern zone may influence the estimation of the MRL (Mean+4SD))

 

pesticide_mrl_guidelines_​animal_model(Dietary burden calculation)

 

animal diets

maybe
Since crops that were typically growing in the southern zone may become easier available/grown in northern zone, a change in the animal feeding pattern may appear

Parameter "animal diet" should be updated, new animal diet data should be collected

fish dietary burden calculator

 

fish diet

no

 

Processing

 

 

no climate sensitive methods are used; therefore no changes are required

 

Rotational crops

 

 

no climate sensitive methods are used; therefore no changes are required
However parameters DT90 and PECs used for the design of rotational crop studies may be influenced by changed E-fate models

 

PRIMo
(Consumer risk assessment)

 

consumption data

maybe
A change of the "typical" consumption may change due to climate change (higher temperatures, change of local grown/available crops)

Parameter "consumption data" should be updated, new consumer survey data should be collected