CAC GL 45GUIDELINE FOR FOOD SAFETY ASSESSMENT OF FOODS DERIVED FROM RECOMBINANTDNA PLANT.docx
《CAC GL 45GUIDELINE FOR FOOD SAFETY ASSESSMENT OF FOODS DERIVED FROM RECOMBINANTDNA PLANT.docx》由会员分享,可在线阅读,更多相关《CAC GL 45GUIDELINE FOR FOOD SAFETY ASSESSMENT OF FOODS DERIVED FROM RECOMBINANTDNA PLANT.docx(15页珍藏版)》请在冰豆网上搜索。
CACGL45GUIDELINEFORFOODSAFETYASSESSMENTOFFOODSDERIVEDFROMRECOMBINANTDNAPLANT
GUIDELINEFORTHECONDUCTOFFOODSAFETYASSESSMENTOFFOODSDERIVEDFROMRECOMBINANT-DNAPLANTS(CAC/GL45-2003)
SECTION1-SCOPE
1.ThisGuidelinesupportsthePrinciplesfortheRiskAnalysisofFoodsDerivedfromModernBiotechnology.Itaddressessafetyandnutritionalaspectsoffoodsconsistingof,orderivedfrom,plantsthathaveahistoryofsafeuseassourcesoffood,andthathavebeenmodifiedbymodernbiotechnologytoexhibitneworalteredexpressionoftraits.
2.Thisdocumentdoesnotaddressanimalfeedoranimalsfedwiththefeed.Thisdocumentalsodoesnotaddressenvironmentalrisks.
3.TheCodexprinciplesofriskanalysis,particularlythoseforriskassessment,areprimarilyintendedtoapplytodiscretechemicalentitiessuchasfoodadditivesandpesticideresidues,oraspecificchemicalormicrobialcontaminantthathaveidentifiablehazardsandrisks;theyarenotintendedtoapplytowholefoodsassuch.Indeed,fewfoodshavebeenassessedscientificallyinamannerthatwouldfullycharacteriseallrisksassociatedwiththefood.Further,manyfoodscontainsubstancesthatwouldlikelybefoundharmfulifsubjectedtoconventionalapproachestosafetytesting.Thus,amorefocusedapproachisrequiredwherethesafetyofawholefoodisbeingconsidered.
4.Thisapproachisbasedontheprinciplethatthesafetyoffoodsderivedfromnewplantvarieties,includingrecombinant-DNAplants,isassessedrelativetotheconventionalcounterparthavingahistoryofsafeuse,takingintoaccountbothintendedandunintendedeffects.Ratherthantryingtoidentifyeveryhazardassociatedwithaparticularfood,theintentionistoidentifyneworalteredhazardsrelativetotheconventionalcounterpart.
5.ThissafetyassessmentapproachfallswithintheriskassessmentframeworkasdiscussedinSection3ofthePrinciplesfortheRiskAnalysisofFoodsDerivedfromModernBiotechnology.Ifaneworalteredhazard,nutritionalorotherfoodsafetyconcernisidentifiedbythesafetyassessment,theriskassociatedwithitwouldfirstbeassessedtodetermineitsrelevancetohumanhealth.Followingthesafetyassessmentandifnecessaryfurtherriskassessment,thefoodwouldbesubjectedtoriskmanagementconsiderationsinaccordancewiththePrinciplesfortheRiskAnalysisofFoodsDerivedfromModernBiotechnologybeforeitisconsideredforcommercialdistribution.
6.Riskmanagementmeasuressuchaspost-marketmonitoringofconsumerhealtheffectsmayassisttheriskassessmentprocess.Thesearediscussedinparagraph20ofthePrinciplesfortheRiskAnalysisofFoodsderivedfromModernBiotechnology.
7.TheGuidelinedescribestherecommendedapproachtomakingsafetyassessmentsoffoodsderivedfromrecombinant-DNAplantswhereaconventionalcounterpartexists,andidentifiesthedataandinformationthataregenerallyapplicabletomakingsuchassessments.WhilethisGuidelineisdesignedforfoodsderivedfromrecombinant-DNAplants,theapproachdescribedcould,ingeneral,beappliedtofoodsderivedfromplantsthathavebeenalteredbyothertechniques.
SECTION2-DEFINITIONS
8.ThedefinitionsbelowapplytothisGuideline:
"Recombinant-DNAPlant"-meansaplantinwhichthegeneticmaterialhasbeenchangedthroughinvitronucleicacidtechniques,includingrecombinantdeoxyribonucleicacid(DNA)anddirectinjectionofnucleicacidintocellsororganelles.
"ConventionalCounterpart"-meansarelatedplantvariety,itscomponentsand/orproductsforwhichthereisexperienceofestablishingsafetybasedoncommonuseasfood[11].
SECTION3-INTRODUCTIONTOFOODSAFETYASSESSMENT
9.Traditionally,newvarietiesoffoodplantshavenotbeensystematicallysubjectedtoextensivechemical,toxicological,ornutritionalevaluationpriortomarketing,withtheexceptionoffoodsforspecificgroups,suchasinfants,wherethefoodmayconstituteasubstantialportionofthediet.Thus,newvarietiesofcorn,soya,potatoesandothercommonfoodplantsareevaluatedbybreedersforagronomicandphenotypiccharacteristics,butgenerally,foodsderivedfromsuchnewplantvarietiesarenotsubjectedtotherigorousandextensivefoodsafetytestingprocedures,includingstudiesinanimals,thataretypicalofchemicalssuchasfoodadditivesorpesticideresiduesthatmaybepresentinfood.
10.Theuseofanimalmodelsforassessingtoxicologicalendpointsisamajorelementintheriskassessmentofmanycompoundssuchaspesticides.Inmostcases,however,thesubstancetobetestediswellcharacterised,ofknownpurity,ofnoparticularnutritionalvalue,and,humanexposuretoitisgenerallylow.Itisthereforerelativelystraightforwardtofeedsuchcompoundstoanimalsatarangeofdosessomeseveralordersofmagnitudegreaterthantheexpectedhumanexposurelevels,inordertoidentifyanypotentialadversehealtheffectsofimportancetohumans.Inthisway,itispossible,inmostcases,toestimatelevelsofexposureatwhichadverseeffectsarenotobservedandtosetsafeintakelevelsbytheapplicationofappropriatesafetyfactors.
11.Animalstudiescannotreadilybeappliedtotestingtherisksassociatedwithwholefoods,whicharecomplexmixturesofcompounds,oftencharacterisedbyawidevariationincompositionandnutritionalvalue.Duetotheirbulkandeffectonsatiety,theycanusuallyonlybefedtoanimalsatlowmultiplesoftheamountsthatmightbepresentinthehumandiet.Inaddition,akeyfactortoconsiderinconductinganimalstudiesonfoodsisthenutritionalvalueandbalanceofthedietsused,inordertoavoidtheinductionofadverseeffectswhicharenotrelateddirectlytothematerialitself.Detectinganypotentialadverseeffectsandrelatingtheseconclusivelytoanindividualcharacteristicofthefoodcanthereforebeextremelydifficult.Ifthecharacterizationofthefoodindicatesthattheavailabledataareinsufficientforathoroughsafetyassessment,properlydesignedanimalstudiescouldberequestedonthewholefoods.Anotherconsiderationindecidingtheneedforanimalstudiesiswhetheritisappropriatetosubjectexperimentalanimalstosuchastudyifitisunlikelytogiverisetomeaningfulinformation.
12.Duetothedifficultiesofapplyingtraditionaltoxicologicaltestingandriskassessmentprocedurestowholefoods,amorefocusedapproachisrequiredforthesafetyassessmentoffoodsderivedfromfoodplants,includingrecombinant-DNAplants.Thishasbeenaddressedbythedevelopmentofamultidisciplinaryapproachforassessingsafetywhichtakesintoaccountbothintendedandunintendedchangesthatmayoccurintheplantorinthefoodsderivedfromit,usingtheconceptofsubstantialequivalence.
13.Theconceptofsubstantialequivalenceisakeystepinthesafetyassessmentprocess.However,itisnotasafetyassessmentinitself;ratheritrepresentsthestartingpointwhichisusedtostructurethesafetyassessmentofanewfoodrelativetoitsconventionalcounterpart.Thisconceptisusedtoidentifysimilaritiesanddifferencesbetweenthenewfoodanditsconventionalcounterpart.[12]Itaidsintheidentificationofpotentialsafetyandnutritionalissuesandisconsideredthemostappropriatestrategytodateforsafetyassessmentoffoodsderivedfromrecombinant-DNAplants.Thesafetyassessmentcarriedoutinthiswaydoesnotimplyabsolutesafetyofthenewproduct;rather,itfocusesonassessingthesafetyofanyidentifieddifferencessothatthesafetyofthenewproductcanbeconsideredrelativetoitsconventionalcounterpart.
UNINTENDEDEFFECTS
14.Inachievingtheobjectiveofconferringaspecifictargettrait(intendedeffect)toaplantbytheinsertionofdefinedDNAsequences,additionaltraitscould,insomecases,beacquiredorexistingtraitscouldbelostormodified(unintendedeffects).Thepotentialoccurrenceofunintendedeffectsisnotrestrictedtotheuseofinvitronucleicacidtechniques.Rather,itisaninherentandgeneralphenomenonthatcanalsooccurinconventionalbreeding.Unintendedeffectsmaybedeleterious,beneficial,orneutralwithrespecttothehealthoftheplantorthesafetyoffoodsderivedfromtheplant.Unintendedeffectsinrecombinant-DNAplantsmayalsoarisethroughtheinsertionofDNAsequencesand/ortheymayarisethroughsubsequentconventionalbreedingoftherecombinant-DNAplant.Safetyassessmentshouldincludedataandinformationtoreducethepossibilitythatafoodderivedfromarecombinant-DNAplantwouldhaveanunexpected,adverseeffectonhumanhealth.
15.UnintendedeffectscanresultfromtherandominsertionofDNAsequencesintotheplantgenomewhichmaycausedisruptionorsilencingofexistinggenes,activationofsilentgenes,ormodificationsintheexpressionofexistinggenes.Unintendedeffectsmayalsoresultintheformationofneworchangedpatternsofmetabolites.Forexample,theexpressionofenzymesathighlevelsmaygiverisetosecondarybiochemicaleffectsorchangesintheregulationofmetabolicpathwaysand/oralteredlevelsofmetabolites.
16.Unintendedeffectsduetogeneticmodificationmaybesubdividedintotwogroups:
thosethatare"predictable"andthosethatare"unexpected".Manyunintendedeffectsarelargelypredictablebasedonknowledgeoftheinsertedtraitanditsmetabolicconnectionsorofthesiteofinsertion.Duetotheexpandinginformationonplantgenomeandtheincreasedspecificityintermsofgeneticmaterialsintroducedthroughrecombinant-DNAtechniquescomparedwithotherformsofplantbreeding,itmaybecomeeasiertopredictunintendedeffectsofaparticularmodification.Molecularbiologicalandbiochem