Concentration models settings

Calculation settings

Table 32 Calculation settings for module Concentration models.
Name Description

Concentration model tier

Custom model, or set according to EFSA Guidance 2012. Note: you may need to set the tier separately in sub-modules.

Default concentration model

The concentration model type that will be used as default for all food/substance combinations. If this model type cannot be fitted, e.g., due to a lack of data, a simpler model will be chosen automatically as a fall-back.

Include MRL fallback model

Use the MRL as fallback model in case the occurrence data is insufficient for other concentration modelling options.

Restrict LOR imputation to authorised uses

Specifies whether imputation of factor x LOR should be limited to authorised uses only.

Non-detects replacement

How to replace non-detects (when not co-modelled, as in censored models).

Factor f (f x LOR)

Replace non-detects by Limit Of Reporting (LOR) times this factor. Constant (f), e.g. 0.5.

MRL Factor (f x MRL)

Use f x MRL as concentration estimate of the MRL models.

Sample based

Include co-occurrence of substances in samples in simulations. If checked, substance residue concentrations are sampled using the correlations between values on the same sample. If unchecked, any correlation between substances is ignored, substance residue concentrations are sampled ignoring the correlations between values on the same sample.

Imputation of missing values

If checked, in procedure of EFSA Guidance 2012, Appendix 1, impute missing values using substance based concentration models. If unchecked, missing values are not imputed (set to 0).

Correlate imputed values with sample potency

If checked, in procedure of EFSA Guidance 2012, Appendix 1, correlate high imputed values with high cumulative potency samples. If unchecked, random imputation.

Use occurrence patterns for imputation

Use of AU data is relevant for imputation of non-detects in the concentration data. Non-detects can be imputed with zero when an agricultural use is un-authorised (all non-detects) or when the AU percentage is less than 100% (part of the non-detects). If checked, AU data is expected and will be used for the imputation of non-detects. If unchecked, 100% potential presence is assumed for all substances on all foods.

Uncertainty settings

Table 33 Uncertainty settings for module Concentration models.
Name Description

Parametric uncertainty

For resample concentrations: specifies whether the uncertainty assessment is based on a parametric approach.