‘The OEL as Instrument in

(1)

TNO Quality of Life Zeist, the Netherlands

‘The OEL as Instrument in

Occupational Safety and Health’

Dr Ruud A. Woutersen Dr Ruud A. Woutersen

Head, Business Unit Toxicology and Applied Pharmacology

(2)

‘The OEL as Instrument in Occupational Safety and Health’

üü Introduction – History of OELIntroduction – History of OEL üü Aim and objectives of OELsAim and objectives of OELs üü Procedure to set an OELProcedure to set an OEL üü STEL, Ceiling levelSTEL, Ceiling level

üü Skin notationSkin notation üü CarcinogensCarcinogens

üü Any differences between SCOEL and DECOS values?Any differences between SCOEL and DECOS values?

(3)

18831883 Earliest OELsEarliest OELs established in Germany established in Germany

üü Standard for quartz set in South Africa gold minesStandard for quartz set in South Africa gold mines üü OELsOELs for 33 substances by US Bureau of Mines for 33 substances by US Bureau of Mines üü Setting OELsSetting OELs introduced in EU legislation introduced in EU legislation

üü Amendment: 2 types of OELsAmendment: 2 types of OELs::

•• Indicative Limit Values (ILVsIndicative Limit Values (ILVs) and) and

•• Binding Limit Values (BLVsBinding Limit Values (BLVs))

History of

History of OELsOELs

(4)

History

History of of OELsOELs in the in the EuropeanEuropean UnionUnion::

19911991 - - FirstFirst set of (27) set of (27) ILVsILVs was was proposedproposed

- - ScientificScientific Expert Group Expert Group was was formedformed

19951995 - - ScientificScientific Committee Committee on on OccupationalOccupational ExposureExposure Limits

Limits ( (SCOELSCOEL))

- - Advisory Advisory CommitteeCommittee for for SafetySafety, , HygieneHygiene and and HealthHealth at Workat Work ( (ACSHHACSHH))

19981998 CouncilCouncil DirectiveDirective definingdefining the the rolerole and and legallegal status of status of OELsOELs

(5)

OELs are meant to protect the majority of the workforce not only duringOELs are meant to protect the majority of the workforce not only during their working life but also during post-working life and in their offspring.

their working life but also during post-working life and in their offspring.

OELs are not intended to protect all individuals within the generalOELs are not intended to protect all individuals within the general population.

population.

In the key document of SCOEL it is described as follows:

The objective in establishing

The objective in establishing OELsOELs is to set limits for exposure via the is to set limits for exposure via the

airborne route such that exposure throughout a working life, will not lead airborne route such that exposure throughout a working life, will not lead to adverse effects on the health of exposed persons and/or their offspring to adverse effects on the health of exposed persons and/or their offspring at any time.

at any time.

Aim Aim

(6)

Step 1:

Step 1: SCOEL SCOEL recommendsrecommends “ “health-basedhealth-based” ” oror “ “pragmaticpragmatic” ”

OELs OELs based based on on toxicologicaltoxicological and other and other health-health- sciences sciences relatedrelated data and

data and considerationsconsiderations Step 2:

Step 2: ACSHH considersACSHH considers the the technicaltechnical and and socio-economicalsocio-economical feasibility

feasibility of the of the OELsOELs recommendedrecommended byby SCOEL, and SCOEL, and recommends

recommends ILVs ILVs oror BLVs BLVs toto the European the European CommissionCommission Step 3:

Step 3: The EuropeanThe European CommissionCommission sets and promulgates sets and promulgates ILVsILVs or or BLVsBLVs

Three-Step Procedure:

(7)

ü ü “ “ Health-based Health-based ” ” OELs OELs

ü ü Indicative Indicative Limit Limit Values Values ( ( ILVs ILVs ) ) ü ü Binding Limit Binding Limit Values Values ( ( BLVs BLVs ) ) ü ü “ “ Pragmatic Pragmatic ” ” OELs OELs

Step 1:

(8)

“ “ Health-based Health-based ” ” OELs OELs

are are recommendedrecommended for for substancessubstances withwith a a thresholdthreshold dosedose below

below whichwhich nono adverseadverse effect is effect is expectedexpected toto occuroccur. . TheyThey leadlead toto either either ILVsILVs oror BLVsBLVs..

Indicative

Indicative Limit Limit ValuesValues ( (ILVsILVs)) Binding Limit

Binding Limit ValuesValues ( (BLVsBLVs))

“Pragmatic“Pragmatic” ” OELsOELs

Step 1:

(9)

Indicative

Indicative Limit Limit Values Values ( ( ILVs ILVs ) )

are set

are set forfor substancessubstances withwith a “ a “Health-basedHealth-based” OEL and ” OEL and forfor which

which nono feasibilityfeasibility problemsproblems are are expectedexpected at the at the workplace

workplace

Binding Limit

Binding Limit ValuesValues ( (BLVsBLVs))

“Pragmatic“Pragmatic” OELS” OELS

“Healh-based“Healh-based” ” OELsOELs

Step 1:

(10)

Binding Limit

Binding Limit Values Values ( ( BLVs) BLVs )

are set

are set forfor substancessubstances without a without a thresholdthreshold dosedose oror withwith a a threshold

threshold dosedose and and feasibilityfeasibility problemsproblems

“Healh-based“Healh-based” ” OELsOELs Indicative

Indicative Limit Limit ValuesValues ( (ILVsILVs))

“Pragmatic“Pragmatic” OELS” OELS

Step 1:

(11)

“ “ Pragmatic Pragmatic ” ” OELs OELs

are are recommendedrecommended for for substancessubstances thatthat mightmight carrycarry some risksome risk at at anyany exposureexposure level. level. TheyThey lead lead toto BLVsBLVs onlyonly..

“Healh-based“Healh-based” ” OELsOELs Indicative

Indicative Limit Limit ValuesValues ( (ILVsILVs)) Binding Limit

Binding Limit ValuesValues ( (BLVsBLVs))

Step 1:

(12)

-- IdentityIdentity

-- Chemical and physical dataChemical and physical data -- Analytical methodsAnalytical methods

-- OccurrenceOccurrence -- ToxicokineticsToxicokinetics

-- Toxicological data comprising human and experimental Toxicological data comprising human and experimental animal data

animal data

-- Mutagenicity, carcinogenicity, reproductive toxicity, Mutagenicity, carcinogenicity, reproductive toxicity, immunotoxicity

immunotoxicity

-- Dose-response/dose-effect relationshipDose-response/dose-effect relationship

OELs are ideally based on the following set of data:

Step 1:

(13)

-- Adequacy of the data baseAdequacy of the data base

-- Selection of the critical effect(sSelection of the critical effect(s))

-- Identification of the relevant study, characterisingIdentification of the relevant study, characterising the key the key effect(s)effect(s) -- Threshold or non-threshold nature of the effectThreshold or non-threshold nature of the effect

-- Dose-response relationshipDose-response relationship -- NOAEL or LOAELNOAEL or LOAEL

-- Application of Uncertainty FactorsApplication of Uncertainty Factors

-- Setting of 8h time weighed average (8hTWA) health-based OELSetting of 8h time weighed average (8hTWA) health-based OEL -- Establishment of a STELEstablishment of a STEL

-- Assignment of a skin notationAssignment of a skin notation

-- Documentation in the recommendationDocumentation in the recommendation

General Working Procedure of SCOEL (I)

Step 1:

(14)

-- Draft Draft summary report (summary report (with with draftdraft OELOEL) ) whichwhich is is publicly publicly available

available for for commentscomments

-- Any Any commentscomments receivedreceived are are studied studied by SCOEL and by SCOEL and incorporated

incorporated into the report into the report ifif consideredconsidered relevant relevant

-- FinalFinal summary report is summary report is publishedpublished byby the Office the Office forfor Publication

Publication of the of the EuropeanEuropean CommunitiesCommunities in in LuxembourgLuxembourg

General Working Procedure of SCOEL (II)

Step 1:

(15)

-- OELs are rounded up or down to decimals of theOELs are rounded up or down to decimals of the integers 1, 2 or 5

integers 1, 2 or 5

…for instance… 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50 …

-- The system is not undisputedThe system is not undisputed

Preferred Value System

Step 1:

(16)

Genotoxic

Genotoxic ( (non-thresholdnon-threshold) ) carcinogenscarcinogens::

SCOEL

SCOEL estimatesestimates degreesdegrees of of cancercancer risk at risk at variousvarious dosedose levelslevels, , usingusing anan appropriate

appropriate extrapolationextrapolation model and model and recommendsrecommends “ “pragmaticpragmatic” ” OELsOELs,, finally

finally leadingleading toto Binding Limit Binding Limit Values set and Values set and promulgatedpromulgated byby the the European

European CommissionCommission

Carcinogens Carcinogens

Non-genotoxic

Non-genotoxic ( (thresholdthreshold) ) carcinogenscarcinogens::

SCOEL

SCOEL usesuses the NOAEL/UF the NOAEL/UF approachapproach, , recommendsrecommends “ “health-basedhealth-based”” OELs, OELs, finallyfinally leadingleading toto eithereither IndicativeIndicative Limit Limit ValuesValues oror Binding Limit Binding Limit Values

Values set and set and promulgatedpromulgated byby the the EuropeanEuropean CommissionCommission Step 1:

Step 1:

(17)

- - Genotoxic Genotoxic CarcinogensCarcinogens:: actingacting throughthrough gene gene mutationsmutations - stochasticallystochastically actingacting carcinogenscarcinogens

- - non-stochasticallynon-stochastically actingacting carcinogenscarcinogens

- - Non-genotoxicNon-genotoxic carcinogenscarcinogens:: do do notnot induceinduce gene gene mutationsmutations

Carcinogens Carcinogens

Step 1:

(18)

-- StochasticallyStochastically acting acting carcinogenscarcinogens: gene : gene mutationmutation induced

induced byby the ( the (ultimateultimate) ) carcinogen carcinogen itselfitself; ; nono threshold

threshold dosedose;; in in principleprinciple, , linear linear extrapolationextrapolation.. Examples

Examples: vinyl chloride, benzo(a)pyrene: vinyl chloride, benzo(a)pyrene, , chromiumchromium VIVI

-- Non-stochasticallyNon-stochastically ((deterministically) deterministically) actingacting carcinogenscarcinogens:: gene

gene mutationsmutations inducedinduced byby a “ a “secondarysecondary” agent;” agent;

threshold

threshold dosedose;; extrapolationextrapolation throughthrough NOAEL/UF NOAEL/UF approach

approach. . ExamplesExamples: cadmium, : cadmium, arsenicarsenic, , crystallinecrystalline silicasilica

Genotoxic

Genotoxic Carcinogens Carcinogens

Step 1:

(19)

No gene

No gene mutationsmutations; ; ThresholdThreshold dosedose; ; ExtrapolationExtrapolation throughthrough NOAEL/UF

NOAEL/UF approachapproach Examples

Examples: : peroxisomeperoxisome proliferatorsproliferators ( (phthalatephthalate esters), esters), cytotoxic

cytotoxic chemicalschemicals ( (butylated butylated hydroxyanisolehydroxyanisole),), immunosuppressors

immunosuppressors ( (azathioprineazathioprine))

Non-genotoxic

Non-genotoxic Carcinogens Carcinogens

Step 1:

(20)

(21)

-- Short-TermShort-Term ExposureExposure LimitsLimits ( (STELsSTELs)) -- CeilingCeiling ValuesValues

-- Skin NotationSkin Notation

-- Biological Biological ExposureExposure Indices Indices

Special aspects

(22)

Definition Definition

The STEL is a limit value above which exposure should not occur The STEL is a limit value above which exposure should not occur and relates to a 15 minutes reference period.

and relates to a 15 minutes reference period.

AimAim

To prevent adverse health affects (irritation, impaired alertness, To prevent adverse health affects (irritation, impaired alertness, nuisance) due to peaks in exposure that will not be controlled by nuisance) due to peaks in exposure that will not be controlled by an 8h TWA limit.

an 8h TWA limit.

Short-term exposure limit (STEL)

(23)

Ceiling levels are short-term limits without a specific time Ceiling levels are short-term limits without a specific time reference period meant for substances producing adverse reference period meant for substances producing adverse effects very rapidly, within minutes of the onset of exposure.

effects very rapidly, within minutes of the onset of exposure.

The limit should not be exceeded at any time.

Ceiling value

(24)

If dermal absorption might contribute substantially (10% or If dermal absorption might contribute substantially (10% or more of the uptake from respiratory exposure at the 8h TWA) more of the uptake from respiratory exposure at the 8h TWA) to the total body burden and consequently to concern

to the total body burden and consequently to concern regarding possible health effects.

regarding possible health effects.

Skin notation

(25)

Biological Limit Values/Biological Exposure Indices

Assessment of exposure to a chemical by a biological method Assessment of exposure to a chemical by a biological method

-- Determination of the substance or its metabolite in Determination of the substance or its metabolite in biologicalbiological medium

medium

-- Measurement of biological effects (serum cholineMeasurement of biological effects (serum choline-esterase -esterase forfor organophosphates)

organophosphates)

-- Measurement of the amount of substance interacting with Measurement of the amount of substance interacting with aa target (

target (carboxyhaemoglobincarboxyhaemoglobin in case of carbon mono in case of carbon mono oxide)oxide) Not for chemicals with local effects.

Not for chemicals with local effects.

(26)

- - The The so-calledso-called tripartitetripartite committeecommittee

- - Consists of Consists of sixsix representatives, representatives, twotwo eacheach fromfrom governments governments ofof EU MemberEU Member StatesStates, employers, employers’ ’ organizationsorganizations and and tradetrade unionsunions -- Evaluates the Evaluates the technicaltechnical, , socialsocial and and economicaleconomical feasibilityfeasibility of of OELs OELs recommendedrecommended byby SCOEL SCOEL

- - RecommendsRecommends OELsOELs toto the the EuropeanEuropean CommissionCommission

Advisory Committee for Safety, Hygiene and Health at Work (ACSHH)

Step 2:

(27)

The European Commission sets and promulgates ILVs or BLVs

Step 3:

(28)

OELs have been established for a fraction of substances which canOELs have been established for a fraction of substances which can occur in the workplace.

occur in the workplace.

Employees in the workplace may be exposed from a few thousand Employees in the workplace may be exposed from a few thousand up to 20 thousand different substances.

up to 20 thousand different substances.

As long as the procedure for setting

As long as the procedure for setting OELsOELs is a national activity, it is a national activity, it will take hundreds of years before

will take hundreds of years before OELsOELs are established for all are established for all substances present in the workplace.

substances present in the workplace.

Answer:

Answer: Efforts need to be made to establish Efforts need to be made to establish OELsOELs which are which are

The most significant problems

(29)

Transparancy

Transparancy and and opennessopenness are major elements are major elements of the of the processprocess of OEL setting.

of OEL setting.

Both Both cancan bebe best best achievedachieved byby a a step-by-stepstep-by-step procedure: procedure:

Step 1:

Step 1: health-basedhealth-based step step withwith publishedpublished HBR-OELHBR-OEL Step 2:

Step 2: feasibilityfeasibility step step withwith publishedpublished operationaloperational OEL OEL Step 3:

Step 3: administrativeadministrative step step withwith publishedpublished administrativeadministrative OEL

OEL

(30)

An OEL -as An OEL -as it is it is published published in in an an official list- official list- should

should be be administrative administrative . .

In In conclusion conclusion (I): (I):

(31)

Preferably

Preferably, the , the administrative administrative OEL should OEL should be be identical

identical to to the the health-based health-based value value ; ; if if this this is is not not feasible

feasible , the reason , the reason(s) (s) for for the the difference difference should should be be spelled out in

spelled out in an an official document official document that that is is publicly publicly available

available. .

In In conclusion conclusion ( ( II II ): ):

(32)

The process of setting an OEL should be open, The process of setting an OEL should be open, transparant

transparant , and documented in detail, and the , and documented in detail, and the document(s

document(s ) should be publicly available. ) should be publicly available.

In In conclusion conclusion ( ( III III ): ):

(33)

-- The EU hasThe EU has a a goodgood systemsystem for setting for setting OELsOELs resultingresulting in ILVsin ILVs oror BLVsBLVs

-- It is a It is a three-stepthree-step procedure procedure -- LackLack of of man-powerman-power

-- Better Better co-operationco-operation withwith OEL committees OEL committees in EU in EU Member

Member StatesStates

‘The OEL as Instrument in