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Predicted no-effect concentration

December 12, 2023

The predicted no-effect concentration (PNEC) is the concentration of a chemical which marks the limit at which below no adverse effects of exposure in an ecosystem are measured. PNEC values are intended to be conservative and predict the concentration at which a chemical will likely have no toxic effect. They are not intended to predict the upper limit of concentration of a chemical that has a toxic effect.[1][2][3] PNEC values are often used in environmental risk assessment as a tool in ecotoxicology.[1][3][4] A PNEC for a chemical can be calculated with acute toxicity or chronic toxicity single-species data, Species Sensitivity Distribution (SSD) multi-species data, field data or model ecosystems data. Depending on the type of data used, an assessment factor is used to account for the confidence of the toxicity data being extrapolated to an entire ecosystem.[3][5]

Calculation methods edit

Assessment factor edit

The use of assessment factors allows for laboratory, single-species and short term toxicity data to be extrapolated to conservatively predict ecosystem effects and accounts for the uncertainty in the extrapolation. The value of the assessment factor is dependent on the uncertainty of the available data and ranges from 1-1000.[1][6][7]

Acute toxicity data edit

Acute toxicity data includes LC50 and EC50 data. This data is frequently screened for quality, relevancy and ideally contains data for species in multiple trophic levels and/or taxonomic groups.[1][6] The lowest LC50 in the compiled database is then divided by the assessment factor to calculate the PNEC for that data. The assessment factor applied to acute toxicity data is typically 1000.[1][6][7]

Chronic toxicity data edit

Chronic toxicity data includes NOEC data. The lowest NOEC value in the test dataset is divided by an assessment factor between 10 and 100 dependent on the diversity of test organisms and the amount of data available. If there are more species or data, the assessment factor is lower.[1][7]

Species sensitivity data edit

A PNEC may also be statistically derived from a SSD which is a model of the variability in the sensitivity of multiple species to a single toxicant or other stressor.[1][8][9] The hazardous concentration for five percent of the species (HC5) in the SSD is used to derive the PNEC. The HC5 is the concentration at which five percent of the species in the SSD exhibit an effect.[10] The HC5 is typically divided by an assessment factor of 1-5.[6] In many cases, SSDs may not exist due to the lack of data on a large number of species. In these cases, the assessment factor approach to derivation of a PNEC should be used.[1][6]

Field data or model ecosystems edit

Field data or model ecosystems data includes field toxicity data and mesocosm toxicity. The magnitude of the assessment factor is study-specific in these types of studies.[1][7]

Applications edit

Environmental risk assessment edit

PNEC is used extensively in Europe by the European Chemicals Agency, the Registration, Evaluation, Authorisation and Restriction of Chemicals program and other toxicology agencies to assess environmental risk.[1][6][7][11][12] PNEC values can be used in conjunction with predicted environmental concentration values to calculate a risk characterization ratio (RCR), also called a Risk Quotient (RQ). RCR is equal to the PEC divided by the PNEC for a specific chemical and is a deterministic approach to estimating environmental risk at local or regional scales.[13] If the PNEC exceeds the PEC, the conclusion is that the chemical poses no environmental risk.[14]

Assumptions edit

Derivation of PNEC for use in environmental risk lacks some scientific validity because the assessment factors are derived empirically.[7] Additionally, PNECs derived from single-species toxicity data also assume that ecosystems are as sensitive as the most sensitive species and that the ecosystem function is dependent on the ecosystem structure.[1]

References edit

  1. ^ a b c d e f g h i j k European Chemicals Bureau. (2003). Technical Guidance Document on Risk Assessment. European Communities 2021-07-06 at the Wayback Machine
  2. ^ Predicted No Effect Concentration. 2015. Greenfacts. Available online at: http://www.greenfacts.org/glossary/pqrs/PNEC-predicted-no-effect-concentration.htm
  3. ^ a b c Lei, Bing L.; Huang, Sheng B.; Jin, Xiao W.; Wang, Zijian (2010). "Deriving the aquatic predicted no-effect concentrations (PNECs) of three chlorophenols for the Taihu Lake, China". Journal of Environmental Science and Health, Part A. 45 (14): 1823–1831. Bibcode:2010JESHA..45.1823L. doi:10.1080/10934529.2010.520495. PMID 20936560. S2CID 9609498.
  4. ^ Manuilova, A. (2003). Methods and Tools Available for Assessment of Environmental Risk. Dantes. 2016-03-04 at the Wayback Machine
  5. ^ "EU Risk assessment summary report". echa.europa.eu. Retrieved 24 September 2023.
  6. ^ a b c d e f Van Sprang, P. 2011. Data compilation, selection and derivation of PNEC values for the aquatic compartment Zinc example. OECD. Available online at: http://www.oecd.org/chemicalsafety/risk-assessment/48720427.pdf
  7. ^ a b c d e f The Edinburgh Centre for Toxicology. Accessed 2015. Environmental Risk Assessment. UNEP/IPCS Training Module No. 3. Section B. Available online at: (PDF). Archived from the original (PDF) on 2015-05-28. Retrieved 2015-05-30.{{cite web}}: CS1 maint: archived copy as title (link)
  8. ^ Jin, Xiaowei; Zha, Jinmiao; Xu, Yiping; Giesy, John P.; Richardson, Kristine L.; Wang, Zijian (2012). "Derivation of predicted no effect concentrations (PNEC) for 2,4,6-trichlorophenol based on Chinese resident species". Chemosphere. 86 (1): 17–23. Bibcode:2012Chmsp..86...17J. doi:10.1016/j.chemosphere.2011.08.040. PMID 21955353.
  9. ^ Shaw-Allen, P. and G. W. Suter II. 2012. Species Sensitivity Distributions (SSDs). CADDIS Volume 4: Data Analysis. EPA. Available online at: http://www.epa.gov/caddis/da_advanced_2.html
  10. ^ Wheeler, J.R; Grist, E.P.M; Leung, K.M.Y; Morritt, D.; Crane, M. (2002). "Species sensitivity distributions: Data and model choice". Marine Pollution Bulletin. 45 (1–12): 192–202. Bibcode:2002MarPB..45..192W. doi:10.1016/S0025-326X(01)00327-7. PMID 12398385.
  11. ^ European Chemicals Agency. 2009. Guidance in a nutshell Chemical safety assessment. Available online at: https://echa.europa.eu/documents/10162/13632/nutshell_guidance_csa_en.pdf 2016-05-09 at the Wayback Machine
  12. ^ European Chemicals Agency. 2008. Guidance on information requirements and chemical safety assessment. Chapter R.10: Characterisation of dose [concentration]-response for environment. Available online at: https://echa.europa.eu/documents/10162/13632/information_requirements_r10_en.pdf 2020-09-18 at the Wayback Machine
  13. ^ MERAG. 2007. Risk characterization: general aspects. Metals Environmental Risk Assessment Guidance. Available online at: https://www.icmm.com/document/253 2016-03-04 at the Wayback Machine
  14. ^ ECETOC. 1993. Environmental Hazard Assessment of Substances. European Centre for Ecotoxicology and Toxicology of Chemicals. Available online at: http://www.ecetoc.org/index.php?mact=MCSoap,cntnt01,details,0&cntnt01by_category=5&cntnt01template=display_list_v2&cntnt01order_by=Number%20Desc&cntnt01display_template=display_details_v2&cntnt01document_id=229&cntnt01returnid=89

December 12, 2023
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The predicted no effect concentration PNEC is the concentration of a chemical which marks the limit at which below no adverse effects of exposure in an ecosystem are measured PNEC values are intended to be conservative and predict the concentration at which a chemical will likely have no toxic effect They are not intended to predict the upper limit of concentration of a chemical that has a toxic effect 1 2 3 PNEC values are often used in environmental risk assessment as a tool in ecotoxicology 1 3 4 A PNEC for a chemical can be calculated with acute toxicity or chronic toxicity single species data Species Sensitivity Distribution SSD multi species data field data or model ecosystems data Depending on the type of data used an assessment factor is used to account for the confidence of the toxicity data being extrapolated to an entire ecosystem 3 5 Contents 1 Calculation methods 1 1 Assessment factor 1 2 Acute toxicity data 1 3 Chronic toxicity data 1 4 Species sensitivity data 1 5 Field data or model ecosystems 2 Applications 2 1 Environmental risk assessment 3 Assumptions 4 ReferencesCalculation methods editAssessment factor edit The use of assessment factors allows for laboratory single species and short term toxicity data to be extrapolated to conservatively predict ecosystem effects and accounts for the uncertainty in the extrapolation The value of the assessment factor is dependent on the uncertainty of the available data and ranges from 1 1000 1 6 7 Acute toxicity data edit Acute toxicity data includes LC50 and EC50 data This data is frequently screened for quality relevancy and ideally contains data for species in multiple trophic levels and or taxonomic groups 1 6 The lowest LC50 in the compiled database is then divided by the assessment factor to calculate the PNEC for that data The assessment factor applied to acute toxicity data is typically 1000 1 6 7 Chronic toxicity data edit Chronic toxicity data includes NOEC data The lowest NOEC value in the test dataset is divided by an assessment factor between 10 and 100 dependent on the diversity of test organisms and the amount of data available If there are more species or data the assessment factor is lower 1 7 Species sensitivity data edit A PNEC may also be statistically derived from a SSD which is a model of the variability in the sensitivity of multiple species to a single toxicant or other stressor 1 8 9 The hazardous concentration for five percent of the species HC5 in the SSD is used to derive the PNEC The HC5 is the concentration at which five percent of the species in the SSD exhibit an effect 10 The HC5 is typically divided by an assessment factor of 1 5 6 In many cases SSDs may not exist due to the lack of data on a large number of species In these cases the assessment factor approach to derivation of a PNEC should be used 1 6 Field data or model ecosystems edit Field data or model ecosystems data includes field toxicity data and mesocosm toxicity The magnitude of the assessment factor is study specific in these types of studies 1 7 Applications editEnvironmental risk assessment edit PNEC is used extensively in Europe by the European Chemicals Agency the Registration Evaluation Authorisation and Restriction of Chemicals program and other toxicology agencies to assess environmental risk 1 6 7 11 12 PNEC values can be used in conjunction with predicted environmental concentration values to calculate a risk characterization ratio RCR also called a Risk Quotient RQ RCR is equal to the PEC divided by the PNEC for a specific chemical and is a deterministic approach to estimating environmental risk at local or regional scales 13 If the PNEC exceeds the PEC the conclusion is that the chemical poses no environmental risk 14 Assumptions editDerivation of PNEC for use in environmental risk lacks some scientific validity because the assessment factors are derived empirically 7 Additionally PNECs derived from single species toxicity data also assume that ecosystems are as sensitive as the most sensitive species and that the ecosystem function is dependent on the ecosystem structure 1 References edit a b c d e f g h i j k European Chemicals Bureau 2003 Technical Guidance Document on Risk Assessment European Communities Archived 2021 07 06 at the Wayback Machine Predicted No Effect Concentration 2015 Greenfacts Available online at http www greenfacts org glossary pqrs PNEC predicted no effect concentration htm a b c Lei Bing L Huang Sheng B Jin Xiao W Wang Zijian 2010 Deriving the aquatic predicted no effect concentrations PNECs of three chlorophenols for the Taihu Lake China Journal of Environmental Science and Health Part A 45 14 1823 1831 Bibcode 2010JESHA 45 1823L doi 10 1080 10934529 2010 520495 PMID 20936560 S2CID 9609498 Manuilova A 2003 Methods and Tools Available for Assessment of Environmental Risk Dantes Archived 2016 03 04 at the Wayback Machine EU Risk assessment summary report echa europa eu Retrieved 24 September 2023 a b c d e f Van Sprang P 2011 Data compilation selection and derivation of PNEC values for the aquatic compartment Zinc example OECD Available online at http www oecd org chemicalsafety risk assessment 48720427 pdf a b c d e f The Edinburgh Centre for Toxicology Accessed 2015 Environmental Risk Assessment UNEP IPCS Training Module No 3 Section B Available online at Archived copy PDF Archived from the original PDF on 2015 05 28 Retrieved 2015 05 30 a href Template Cite web html title Template Cite web cite web a CS1 maint archived copy as title link Jin Xiaowei Zha Jinmiao Xu Yiping Giesy John P Richardson Kristine L Wang Zijian 2012 Derivation of predicted no effect concentrations PNEC for 2 4 6 trichlorophenol based on Chinese resident species Chemosphere 86 1 17 23 Bibcode 2012Chmsp 86 17J doi 10 1016 j chemosphere 2011 08 040 PMID 21955353 Shaw Allen P and G W Suter II 2012 Species Sensitivity Distributions SSDs CADDIS Volume 4 Data Analysis EPA Available online at http www epa gov caddis da advanced 2 html Wheeler J R Grist E P M Leung K M Y Morritt D Crane M 2002 Species sensitivity distributions Data and model choice Marine Pollution Bulletin 45 1 12 192 202 Bibcode 2002MarPB 45 192W doi 10 1016 S0025 326X 01 00327 7 PMID 12398385 European Chemicals Agency 2009 Guidance in a nutshell Chemical safety assessment Available online at https echa europa eu documents 10162 13632 nutshell guidance csa en pdf Archived 2016 05 09 at the Wayback Machine European Chemicals Agency 2008 Guidance on information requirements and chemical safety assessment Chapter R 10 Characterisation of dose concentration response for environment Available online at https echa europa eu documents 10162 13632 information requirements r10 en pdf Archived 2020 09 18 at the Wayback Machine MERAG 2007 Risk characterization general aspects Metals Environmental Risk Assessment Guidance Available online at https www icmm com document 253 Archived 2016 03 04 at the Wayback Machine ECETOC 1993 Environmental Hazard Assessment of Substances European Centre for Ecotoxicology and Toxicology of Chemicals Available online at http www ecetoc org index php mact MCSoap cntnt01 details 0 amp cntnt01by category 5 amp cntnt01template display list v2 amp cntnt01order by Number 20Desc amp cntnt01display template display details v2 amp cntnt01document id 229 amp cntnt01returnid 89 Retrieved from https en wikipedia org w index php title Predicted no effect concentration amp oldid 1178696942, wikipedia, wiki, book, books, library,

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