OfficialJournaloftheEuropean Communities 265
26.11.66 OFFICIAL JOURNAL OFTHEEUROPEAN COMMUNITIES 3693/66
COUNCIL DIRECTIVE
of27October1966
amending theDirectives layingdownthebasicstandardsfortheprotection ofthehealth
ofworkersandthegeneralpublicagainstthedangersarisingfromionisingradiations
(66/45/Euratom )
arisingfromionisingradiations ,asamendedbythe
CouncilDirectiveof5March1962,3shallbeamended
inaccordance withArticles2to20.
Article2THECOUNCIL OFTHEEUROPEAN ATOMIC
ENERGY COMMUNITY ,
HavingregardtotheTreatyestablishing theEuropean
AtomicEnergyCommunity ,andinparticular Articles
31and32thereof;
HavingregardtotherequestoftheFederalRepublic
ofGermanyof23March1960forthebasicstandards
toberevisedandsupplemented ;
HavingregardtotheOpinionofthespecialistgroup
appointed bytheScientificandTechnical Committee
fromamongscientificexpertsintheMemberStates;
HavingregardtotheOpinionoftheEconomic and
SocialCommittee ;
HavingregardtotheproposalfromtheCommission ;
Afterconsulting theEuropeanParliament 1;
Whereas thebasicstandards mustbeadjustedin
accordance withthemostrecentscientificdata;
Whereasitisnecessarytotakeaccountofexperience
acquiredfromthepracticalapplication ofthebasic
standards bytheMemberStates;InArticle1(1)theseventhandeighthsubparagraphs
shallbereplacedbythefollowing :
'Exposure':anyexposureofpersonstoionising
radiation ;adistinction ismadebetween :
—externalexposure ,wherethesourceisoutside
thebody;
—internalexposure ,whichiscausedbytheintro­
ductionofradioactive substances intothebody;
and
—totalexposure ,whichisthesumofexternal
exposureandinternalexposure .
'Plannedabnormalexposure':externalandinternal
(orexternalorinternal)exposureasaresultof
whichamaximum permissible doseisexceededin
occupationally exposedpersons,andforwhichthe
riskhaspreviously beenstudiedandaccepted .It
maybeauthorised onlyincasesofabsolute
necessity .
'Unplanned abnormal exposure':externaland
internal (orexternalorinternal )exposurewhich
isofafortuitous natureandwhichinvolves ex­
ceedingamaximum permissible doseforoccu­
pationally exposedpersons .HASADOPTED THISDIRECTIVE :
Article 1
TheCouncilDirectivesof2February1959layingdown
thebasicstandardsfortheprotection ofthehealthof
workersandthegeneralpublicagainstthedangers
2OJNo11,20.2.1959 ,p.221/59.
3OJNo57,9.7.1962,p.1633/62. 1OJNo96,2.6.1965,p.1696/65.

266 OfficialJournaloftheEuropean Communities
Article3
TheTableinArticle1(4)shallbereplacedbythe
following :Asingledoseof3remmustbeavoidedwherever
possible.'
Subparagraphs (b)to(d)shallremainunaltered .
Article5
Articles 8and9shallbedeleted .Radiation RBE1
X-andgammarays,electronsandbeta
raysofallenergies 1
Neutrons 2to1052
Protons 10'
Alphaparticles 10
Heavyrecoilnuclei 20Article6
Article10shallberenumbered Article 8andbe
amended toreadasfollows :
'Article8
1Inthecaseofirradiation ofthelensesoftheeyes,theRBEmustbe
multiplied by:
—afactorof1whenitsvalueisequalto1;
—afactorof3whenitsvalueishigherthanorequalto10;
—afactorbetween 1and3,obtained byinterpolation ,forRBEvalues
between 1and10.
2SeeAnnex2.Wherethereispartialexposureofthebody,during
whichthedosesreceivedbytheblood-forming
organsandthegonadsorbyoneorotherofthose
organsdonotexceedthelimitssetbythebasic
formula,themaximum permissible doseshallbe:
(a)forexternalexposureoftheextremities (hands,
forearms ,feet,ankles),15remperthirteen
weeksand60remperyear;
(b)forexternalexposure oftheskinorbone,with
theexceptionoftheextremities specifiedin(a)
above,8remperthirteenweeksand30rem
peryear;
(c)forexposureofotherorgansindividually ,4rem
perthirteenweeksand13remperyear.'Article4
(a)TheheadingofArticle7shallbedeleted.
(b)Article7(1)shallbereplacedbythefollowing :
'§1—Themaximum permissible doseforan
occupationally exposedpersonshallbeexpressed
inremandshallbecalculated byreferencetoage
andanaverageannualdoseof5rem.
Themaximum permissible doseforapersonofa
givenage,receivedbytheblood-forming organs
andthegonads (orbyoneorotherofthose
organs),shallbecalculated inaccordance withthe
basicformula :Article7
Article11shallberenumbered Article9.
Article8
D=5(N—18)
whereD—doseinrem
N=ageinyears.'Article12shallberenumbered Article10.Thefirst
sentenceofthatArticleshallbeamended toreadas
follows :
'Forthepopulation asawhole,themaximum
permissible genetically significant doseshallbe
5remperhead,accumulated uptothirtyyears.
ofage.'
Article9'(c)Article7(3)shallbeamendedtoreadasfollows :
'§3—Themaximum cumulative doseinany
periodofthirteenconsecutive weeksshallnot
exceed3rem.Thefollowing shallbetakeninto
accountincalculating thedose:
(a)Personsagedeighteenandovermayreceivea
cumulative doseof3rem(distributed over
thirteenconsecutive weeks),providedthatthe
basicformulaiscompliedwithandthatthe
doseaccumulated overoneyearneverexceeds
12rem.Article13shallberenumbered Article11.Paragraph 3
ofthatArticleshallbeamendedtoreadasfollows :
'TheTableinAnnex2showstheneutronfluxas
imparting adoserateof2'5millirem/hoursasa
functionoftheneutronenergyandthecorrespond­
ingRBEvalues.'

OfficialJournaloftheEuropean Communities 267
Article10 Article14
ABNORMAL EXTERNAL EXPOSUREArticle14shallberenumbered Article12andamended
toreadasfollows :
'Article12 §1—"Plannedabnormalexternalexposure"
(a)Thedosedeliveredononeoccasionormorein
thecourseofaplannedabnormal external
exposure shallnotexceed12rem.Thisdose
shallbeaddedtothedoseaccumulated upto
thetimeoftheabnormalexposure .
(b)Ifthecumulative dosethuscalculated isbelow
themaximum permissible dosecalculated
according tothebasicformulasetoutin
Article7(1)andifthequarterlydoseexceeds
3rem,subsequent exposures shallbereduced
toamaximum doseof1*5remperquarteruntil
suchtimeasthevaluesderivedfromapplying
theprovisions ofArticle7(3)arerestored .
(c)Ifthecumulative dosethuscalculated exceeds
themaximum permissible dosecalculated
according tothebasicformulasetoutin
Article7(1),subsequent exposures shallbe
reducedtoamaximum doseof2*5remper
yearuntilsuchtimeasthecumulative dose
conformsagaintothebasicformula.
(d)Nowomanofreproductive capacitymaybe
subjectedtosuchanexposure .§1—"Maximum permissible contamination of
persons"meanscontamination resultingfromthe
inhalation oringestionofairorwatercontaminated
tothemaximum permissible concentrations calcu­
latedinaccordance withAnnex3.
§2—ThevaluesshowninAnnex3areapplicable
fordetermining themaximum permissible concen­
trationsininhaledairorindrinkingwater;they
mustbeconsidered asaveragevaluescoveringa
periodofthirteenconsecutive weeks.
§3—Thesevaluesrelatetocontinuous exposure ,
calculated onthebasisofonehundredandsixty­
eighthoursperweek,foroccupationally exposed
persons.Theymustbemultiplied byafactorof3
torelatetoaworkingweekoffortytoforty-eight
hours.
§4—Theintroduction atasingletimeofaquantity
ofradioactive nuclidesequaltothatwhichwould
beintroduced inthirteenconsecutive weeksonthe
basisofthemaximum permissible concentrations
ascalculated fromAnnex3mustbeavoided
whereverpossible .
§5—Outsidethecontrolled areas,forpersons
belonging tothepopulation groupdefinedin(c)
ofthefifthsubparagraph ofArticle1(2),the
maximum permissible concentrations whichdeter­
minethemaximum permissible contaminations
shallbelaiddownasone-tenth ofthevaluesshown
intheTablesinAnnex3.Theymustbecon­
sideredasaveragevaluesrelatingtoaperiodofa
year.
§6—Wherecontamination resultsfromamixture
ofradioactive nuclides,TableC,DorEinAnnex3,
asthecasemaybe,shallapply.'
Article11
Article15shallbedeleted.§2—"Unplanned abnormal externalexposure"
(a)Whenadosedeliveredduringanunplanned
abnormalexternalexposuredoesnotexceed25
rem,paragraph 1(b)or(c)shallbeapplicable .
(b)Whenthedoseexceeds25rem,Article25(3)
shallbeapplicable .
§3—"Partialplannedabnormalexternalexposure"
(a)Thedosedeliveredononeormoreoccasions
inthecourseofapartialplannedabnormal
externalexposuremustnotexceed:
—inthecaseoftheextremities (hands,fore­
arms,feet,ankles):60rem;
—inthecaseoftheskin(withtheexceptionof
thatoftheextremities ):30rem;
—inthecaseofthelensesoftheeyes:15rem.
Thedosesreceivedshallbeaddedtothedoses
accumulated inthecurrentyear.
(b)Forsubsequent exposures oftheextremities ,
theskin(withtheexception ofthatofthe
extremities )andthelensesoftheeyes,the
maximum permissible dosestobetakeninto
consideration shall,untilsuchtimeastheArticle12
Theprovisions ofthenewArticles13,14and15shall
beasfollows :
'Article13
TOTAL EXPOSURE
Inthecaseoftotalexposure ,thesumofthedoses
duetoexternalexposureandinternalexposure
shallbecalculated byanappropriate methodand
shallbewithinthemaximum permissible doses.

268 OfficialJournaloftheEuropean Communities
integrated valuesderivedfromapplyingthe
provisions ofthatArticlearerestored,be
reducedtohalfofthedoselaiddownin
Article8.
§4—"Partialunplanned abnormal exposure"equaltohalfthevaluescalculated inaccordance
withAnnex3andmustremainsoforsuchtime
aswouldberequiredtoaccumulate ,bycon­
tinuousexposureunderthesameconditions ,
thequantityofradionuclides introduced into
thebodyasaresultoftheplannedabnormal
internalexposure .
(d)Nowomanofreproductive capacitymaybe
subjectedtosuchanexposure .
§2—"Unplanned abnormalinternalexposure"
(a)"Whenthequantityofradioactive nuclides
introduced intothebodyduringanunplanned
abnormalinternalexposureislessthandouble
thequantityaslaiddowninparagraph 1(a),
theprovisions ofparagraph 1(c)shallbe
applicable .
(b)Whenthecontamination exceedsthelimitlaid
downin(a)ofthisparagraph ,Article25(3)
shallbeapplicable .'(a)Whenadosedeliveredinthecourseofapartial
unplanned abnormal externalexposure does
notexceed :
—120reminthecaseoftheextremities (hands,
forearms ,feet,ankles);
—60reminthecaseoftheskin(withthe
exception ofthatoftheextremities );
—30reminthecaseofthelensesoftheeyes;
paragraph 3(b)shallbeapplicable .
(b)Whenthedoseexceedsthevaluesspecified
in(a),Article25(3)shallbeapplicable .
Article13 Article15
ABNORMAL INTERNAL EXPOSUREArticle16shallbereplacedbythefollowing :
1Article16
Thevaluesofmaximum permissible exposureand
contamination applicable toconditions otherthan
thoseobtaining inthecaseofoccupationally
exposedpersonsshallbecalculated fromthemaxi­
mumpermissible dosesaslaiddowninPartIII.'
Article14§1—"Plannedabnormalinternalexposure"
(a)Aplannedabnormalinternalexposureshallbe
permittedonlyifitcannotbeavoidedbytaking
allthenecessary safetymeasures .Shouldsuch
exposureproveunavoidable ,thequantityof
radioactive nuclidesintroduced intothebody
atonetimeormorethanoncemustnotexceed
thequantitywhichwouldresultfromexposure ,
overaperiodofoneyear,tothemaximum
permissible concentrations asshowninAnnex3
foroccupationally exposedpersons .1
(b)Everyplannedabnormalinternalexposuremust
beenteredinthephysicalcontrolrecords
(Article22(2))andinthemedicalfileofthe
workerconcerned (Article26),togetherwith
theestimated valueoftheabsorbed doseand
oftheuptakeresultingfromthatexposure .
(c)Inthecaseofsubsequent internalexposure ,the
maximum permissible concentrations tobe
takenintoconsideration mustbeatthemostArticle25(3)shallbereplacedbythefollowing :
'§3—Specialsurveillance
(a)Specialsurveillance shallbearrangedinthe
eventofabnormalexposure .
(b)Routinemedicalexaminations shallbesup­
plemented byanyexaminations ,decontami­
nationmeasuresandurgentremedialtreatment
considered bythemedicalpractitioner .tobe
necessary .
(c).Themedicalpractitioner shalldecidewhether
theworkershouldremainatwork,bemoved
away,orbeisolatedandwhetherurgentmedical .
treatmentshouldbegiven.'1ThisquantityX(incuries)maybecalculated fromthe
maximum permissible concentrations inairforoccu­
pationally exposedpersonsforfortytoforty-eight hours
perweekbythefollowingformula :
X=2500.q
Article15 qbeingthreetimesthevalueshownintheTablesin
Annex3.Thecoefficient 2500isobtained onthebasis
ofaninhalation of10m3ofairperdayforfivedaysper
weekandfiftyweeksperyear. Annex1shallbereplacedbythefollowing :

OfficialJournaloftheEuropean Communities 269
'ANNEX 1
1—Activities .belowwhichtherequirements forreportingandobtainingpriorauthorisation
maybewaived :
Nuclidesofveryhighradiotoxicity :10"7curies;
Nuclidesofhighradiotoxicity :10"6curies;
Nuclidesofmoderateradiotoxicity :10-5curies;
Nuclidesoflowradiotoxicity :10"4curies;
2—Theprincipalradioactive nuclidesareclassified asfollows,according totheirrelative
radiotoxicity :
(a)Veryhighradiotoxicity :
Ac227Am241Am242mAm243Cf249Cf250Cf251Cf252Cf254Cm242Cm243Cm244Cm245Cm246
Cm248Es254Es255Np237Pa231Pb210Po210Pu238Pu239Pu240Pu241Pu242Ra223Ra226Ra228
•Th227Yh228Th230U230Uu233U234
(b)Highradiotoxicity :
Ac228Ag110mAm242At211Ba140Bi207Bi210Bk249Ca45Cd115mCe144Cf253CI36Cm247Co56
Co60Cs134Cs137Es253Es254mEu152(13years)Eu154Fm255Fm256Hf181I124I126I131I133
In114mIr192Mn54Na22Pa230Pb212Pu244Ra224Ru106Sb124Sb125Sc46Sr89Sr90Ta182Tb160
Ye127mYe129mTh234TlTm170U236Y91Zr
(c)Moderateradiotoxicity :
A41Ag105Ag111Am244As73As74As76As77Au196Au198Au199Ba131Be7Bi206Bi212Bk250
Br82C14Ca47Cd109Cd115Ce141Ce143CI38Co57Co58Cr51Cs131Cs136Cu64Dy165Dy166
Er169Er171Eu152(9h)Eu155F18Fe52Fe55Fe59Fm264Ga72Gd153Gd159Hg197Hg197mHg203
Ho166!130I132I134I135Jn115mJr190Ir194K42K43Kr85mKr87La140Lu177Mn52Mn56Mo"
Na24Nb93mNb95Nd147Nd149Ni63Ni65Np239Os185Os191Os193P32Pa233Pb203Pd103
Pd109Pm147Pm149Pr142Pr143Pt191Pt193Pt197Pu243Rb86Re183Re186Re188Rh105Rn220
Rn222Ru97Ru103Ru105S35Sb122Sc47Sc48Se75Si31Sm151Sm153Sn113Sn125Sr85Sr91Sr92
Tc98Tc97Tc97mTc"Te125mTe127Te129Te131mTe132Th231Tl200Tl201Tl202Tm171
U240_J_Νp240V48^181^185"W187Xe135Y90Y92Y93Yb175^η65Zn69mZr97
(d)Lowradiotoxicity :
A37Cm249Co58mCs134mCs135Ge71H3I129In113mIn115Kr85Nb97Nd144Ni59O15Os191m
Pt193mPt197mRb87Re187 Sm147Sj.85mT(.96mTc99mThnat.!-Th232Unat.::"'fU235
U238Xe131mXe133Y91mZn69Zr93
§3—InthecaseofthenuclidesIn115,Nd144,Rb87,Re187,Sm147therequirements forreporting
andobtainingpriorauthorisation maybewaived,irrespective ofthequantities used.
§4—Inthecaseofamixtureofradioactive nuclidesbelongingtodifferentradiotoxicity groups,
therequirements forreportingandobtainingpriorauthorisation maybewaivedifthe
sumoftheratiosbetweentheactivityofeachoftheradioactive nuclidesandthelimit
laiddowninparagraph 1forthegrouptowhichitbelongsislessthan1.
*Bycustom,onecurieofnaturalthoriumcorresponds to:
3-7.1010dis/secofTh23*and
3-7.1010dis/secofTh238.
**Bycustom,onecurieofnaturaluraniumcorresponds to:
3-7.1010dis/secofU238,
3-7.1010dis/secofU234and
1-7.109dis/secofU836.'

OfficialJournaloftheEuropean Communities 270
5—Theradionuclides notshownintheradiotoxicity groupsinparagraph 2andtheradio­
toxicityofwhichisuncertainorunknownmustbeconsidered asbelongingtothehighest
radiotoxicity category.'
Article16
Annex2shallbereplacedbythefollowing :
'ANNEX 2
Tableshowingtheneutronfluxasdelivering adose-rateof2-5mremperhourasafunctionof
theneutronenergyandthecorresponding RBEvalues
Neutronenergy RBE1Neutron flux
(neutrons/cm2sec)
Thermal 3 670
100eV 2 500
5keV' 2-5 570
20keV .5 280
100keV 8. 80
0-5MeV 10 30
1MeV 10-5 18
2-5MeV ■8 20
5MeV 7 18
10MeV 6;5 17
1Inthecaseofneutronsofunknown energytheRBEistakenasbeing10.'
Article17
InAnnex3,TableAshallbeamendedtoreadasfollows :
(a)Thetitleshallbewordedasfollows :
'A.Maximum permissible concentration (MPC)ofidentifiedradionuclides indrinkingwater
andinairinhaledforcontinuous exposureofoccupationally exposed -persons'
Thesentenceafterthetitle—'(Tablebasedonvaluesrecommended in1959bythe
International Commission onRadiological Protection )(ICRP)'—shallbedeleted.
Thecolumnheadingsshallbeasfollows :
RadionuclideElement
(Atomicnumber)Form
(b)MPCinwater
(c)MPCinair
'(c)
(b)InNote(c)thewords'Article14(4),(5)and(6)'shallbereplacedbythewords
'Article12(3)'.

OfficialJournaloftheEuropean Communities 271
(c)Thedataconcerning theelementsamericium ,berkelium ,californium ,curium,
plutonium ,strontiumanduraniumshallbereplacedbythefollowing :
Element
(Atomicnumber)RadionuclideForm
bMPCinwater
cMPCinair
C
Americium
(95)Am241 sol.
insol.4.IO'5
3.IO"42.IO"12
4.IO"11
Am242m sol.
insol.4.IO"5
9.IO"42.IO-12
9.IO-11
Am242 sòl.
insol.IO"3
IO"3IO"8
2.IO"8
Am243 .sol.
insol.4.IO"5
3.IO'42.IO"12
4.IO'11
Am244 sol.
insol.0-05
0-05IO"6
8.IO"6
Berkelium
(97)Bk249 sol.
insol.6.IO"3
6.IO"33.IO10
4.IO'8
Bk250 sol.
insol.2.IO"3
2.IO"35.IO"8
4.IO"7
Californium
(98)Cf249 sol.
insol.*4.IO"5
2.IO"45.IO"13
3.IO11
Cf250 sol.
insol.1.io-4
3.IO"42.IO'12
3.IO'11
Cf251 sol.
insol.4.IO"5
3.IO"46.IO"13
3.IO'11
Cf252 sol.
insol.7.IO"5
7.IO'52.IO'12
1.io-11
Cf253 1sol.
insol.io-3
io-33.IO'10
3.1010
Cf254 sol.·
insol.IO"6
IO"6'2.IO'12
2.1012
Curium
(96)Cm242 sol.
insol.2.IO"4
2.IO"44.IO11
6.IO11
Cm243 sol.
insol.5.IO'5
2.IO'42.IO"12
3.IO"11
Cm244 sol.
insol.7.IO'5
3.IO"43.IO"12
3.IO"11
Cm245 sol.
insol.4.IO"5
3.IO'42.IO'12
4.IO"11
Cm246 sol.
insol.4.IO"5
3.IO"42.IO"12
4.IO11
Cm247 sol.
insol.4.IO"5
2.IO'42.IO"12
4.IO"11
Cm248 sol.
insol.4.IO"6
IO"52.IO"13
4.IO"12
Cm249 sol.
insol.0-02
0-024.IO"6
4.10-®

272 OfficialJournaloftheEuropean Communities
Element
(Atomicnumber)'Radionuclide:Form
bMPCinwater
cMPCinair
c
Plutonium
(94).pu238 sol.
insol.5.IO"5
3.IO"47.IO"13
1.IO"11
Pu239 sol.
insol.5.IO"5
3.IO'46.IO'13
1.IO"11
Pu240 sol.
insol.5.IO"5
3.IO"46.IO"13
1.IO"11
Pu241 sol.
insol.2.IO'3
1.io-23.IO"11
1.IO"8
Pu242 sol.
insol.5.IO"5
3.10-46.IO"13
1.IO"11
Pu243 sol.
insol.3.IO"3
3.IO"36.IO"7
8.IO"7
Pu244 sol.
insol.4.IO"5
IO"46.IO"13
IO"11
Strontium
(38)Sr85m sol.
insol.7.IO"2
7.IO"21.io-5
1.io-5
Sr85 sol.
insol.1.IO"3
2.IO"38.IO"8
4.IO'8'
Sr88 sol.
insol.1.IO-4
3.IO"41.IO-8
1.IO"8
*Sr90 sol.
insol.4.IO"6
4.IO44.IO'10
2.IO-9
Sr91 sol.
insol.7.IO"4
5.IO"42.IO"7
9.IO"8
Sr92 sol.
insol.7.IO"4
6.IO"4'2.IO"7
1.IO"7
Uranium
(92)U230 sol.
insol.2.IO'5
5.IO'5io-10·
4.IO'11
U232 sol.
insol.8.IO"6
3.IO"43.IO'11
9.IO"12
u238 sol.
insol.4.IO"5
3.IO'42.IO"10
4.IO"11
U284 sol.
insol.4.IO"5
3.IO"42.IO"10
4.IO:11
U235 sol.
.insol.4.IO"5
3.IO"42.IO"10
4.IO"11
U236 sol.
insol.5.IO"5
3.IO'42.IO"10
4.IO"11
U238 sol.
insol.6.IO"6
4.10'"43.IO"11·
5.IO'11
Unat.* sol.
insol.6.IO"6
2.IO"43.IO"11
2.IO11
*Bycustom,onecurieofnaturaluraniumcorresponds to:
3-7.1010dis/secofU238,
3-7.1010dis/secofU234and
1-7.109dis/secofU235.

OfficialJournaloftheEuropean Communities 273
Element
(Atomicnumber)RadionuclideForm
faMPCinwater
CMPCinair
C
Uranium (Cont'd)
(92)U240+Np240sol.
insol.3.IO"4-
3.10-48.IO"8
6.IO"8
(d)Thefollowingdataconcerning theelementseinsteinium andfermiumshallbeinserted
intheTable:
Element
{Atomicnumber )RadionuclideForm
.bMPCinwater
CMPCinair
c
Einsteinium
(99)Es253 sol.
insol.2.IO"4
2.IO"43.IO"10
2.IO"10
Es254m sol.
insol.2.IO"4
2.IO"42.IO"9
2.IO"9
Es254 sol.
insol.io-4
IO"46.IO12
4.IO"11
Es255 sol.
insol.3.IO"4
3.IO"42.IO'10
10-10
Fermium
(100)Fm254 sol.
insol.IO"3
IO"32.IO"8
2.IO"8
Fm255 sol.
insol.3.IO'4
3.IO"46.IO9
4.IO"9
Fm256 sol.
insol.9.IO"6
9.IO"6IO"9
6.IO'10
(e)Thenoteconcerning naturalthoriumshallbereplacedbythefollowing :
'Bycustom,onecurieofnaturalthoriumcorresponds to:
3-7.1010dis/secofTh232and
3.7.1010dis/secofTh228.'
Article18
InAnnex3,TableC,thewords:
'K=10foracontinuous exposure (onehundredandsixty-eight hoursperweek)outsidethe
controlled area'
shallbereplacedbythefollowingwords:
'K=10foracontinuous exposureoutsidethecontrolledareainthecaseofpersonsbelonging
tothegroupdefinedin(c)ofthefifthsubparagraph ofArticle1(2).'

274 OfficialJournaloftheEuropean Communities
Article19
Annex3,TableDshallbereplacedbythefollowing :
'D.Maximum permissible concentration ofamixtureofunidentified radionuclides jndrinking
waterforcontinuous exposureofoccupationally exposed-persons
Typesofmixture MPCinμα/ml.
—Anymixtureofalpha,beta,gammaemitters 1io-7
—Anymixtureofalpha,beta,gammaemitters,iftheRa22®andthe
Ra228canbedisregarded "' 1IO-6
—;Anymixtureofalpha,beta,gammaemitters,iftheSr90,I129,Pb210,
Ra226,Ra228,U238,Unat.,Cm248andÇf254canbedisregarded "' 7IO-6
—Anymixtureofalpha,beta,gammaemitters,iftheSr90,1126,1129,1131,
Pb210,Po210,At211,Ra223,Ra226,Ra228,Rl228,Pa231,Thnat.,U232,U238,
Unat.,Cm248,Cf254andFm256canbedisregarded * 2io-5
—Anymixtureofalpha,beta,gammaemitters,iftheSr90,1126,1129,1131,
Pb210,Po210,At211,Ra223,Ra224,Ra226,Ac227,Ra228,Th230,U230,Pa231,
Th232,Thnat.,U232,U238,Unat.,Cm248,Cf254andFm256canbe
'disregarded * 3IO-5
*"Canbedisregarded "impliesthattheconcentration oftheseradionuclides inwaterrepresents onlyanegligiblefraction
ofthemaximum permissible concentration showninTableAinAnnex3.'
Article20
Annex3,TableEshallbereplacedbythefollowing :
'E.Maximum permissible concentration ofamixtureofunidentified radionuclides ininhaledair
forexposureofoccupationally exposedpersons
Typesofmixture "- MPCn[¿Ci/ml
—Anymixtureofalpha,beta,gammaemitters .2.IO"13
—Anymixtureofalpha,beta,gammaemitters,ifthePa231,Pu239,Pu240,
Pu242,Pu244,Cm248,Cf249andCf251canbedisregarded * 7.IO-13
—Anymixtureofalpha,beta,gammaemitters,iftheAc227,Th230,Pa231,~
Pu238,Pu239,Pu240,Pu242,Pu244,Cm248,Cf249andCf251canbedisre­
garded* r.IO-12.
—Anymixtureofbetaandgammaemitters,ifalphaemitterscanbe
disregarded ,andifAc227,Am242andCf254canbedisregarded * 1.IO-11
—Anymixtureofbetaandgammaemitters,ifthealphaemitterscan
.bedisregarded andifPb210,Ac227,Ra228,Pu241,Am242mandCf254can
bedisregarded * 1io-10
—Anymixtureofbetaandgammaemitters,ifthealphaemitterscan
bedisregarded andiftheSr90,I129,Pb210,Ac227,Ra228,Pa230,Pu241,
Am242111,Bk249,Cf253,Cf254,Es255andFm256canbedisregarded ;' 1IO-9
*"Canbedisregarded "impliesthattheconcentration ofthese-radionuclides intheairrepresents onlyanegligible fraction
.ofthemaximum permissible concentration showninTableAinAnnex3.'
.Article21
ThisDirective isaddressed totheMemberStates:
DoneatBrussels,27October1966.
FortheCouncil
ThePresident
J.M.A.H.LUNS