Step by Step Approach for GPS Risk Assessment

Transcription

1 Step by Step Approach for GPS Risk Assessment 1) Tier Categorization and Prioritization 2) Hazard Characterization By Mr. Krittanon Yuen-ying (Product Regulatory) Dow Chemical Thailand Limited Responsible Care Management Committee of Thailand Chemical Industry Club, The Federation of Thai Industries 6 June 2014, Bangkok, Thailand

2 GPS risk assessment process Step1 : Select Substances for Risk Assessment Section One Step2 : Gather Information Step3 : Allocate Substances to Tiers Tier 1, 2, 3 and 4 Step4 : Complete Tier-specific Information Step5 : Hazard Characterization Step6 : Exposure Assessment Step7 : Risk Characterization Step8 : Document Outcome

3 STEP 1: Select substances for GPS risk assessment In Step 1 you will: Make a list of all chemicals you place on the market 1. First, make an inventory of the chemicals your company sells into the market or transports off the production site (keep strictly company internal due to antitrust / competition law compliance) 2. Second, establish whether there are any exemptions to the risk assessment

4 STEP 1: Select substances for GPS risk assessment 1. Are sold ( in commerce ) or transported world-wide in quantities of more than 1 metric ton per year by company and those that 2. Pose a major threat to human health and/or the environment (e.g. known carcinogens, reproductive hazards, extremely toxic, persistent and bioaccumulating) - even if they are sold or transported in smaller amounts than 1 metric ton per year.

5 STEP 1: Select substances for GPS risk assessment After gathering the inventory those chemicals fulfilling the following criteria should be prioritized first: Classification and Labeling Status» e.g. classified as hazardous to human health and / or environment Exposure considerations» e.g. end consumer product with high likelihood of exposure Business interest» e.g. high production volume, market importance Other consideration based on company internal strategies» Internal Product Stewardship goals

6 STEP 2: Gather Information In Step 2 you will: Gather available information on each chemical in order to be able to judge its priority for the subsequent risk assessment 3 separate types of information: Standard parameters Hazard information Exposure information

7 STEP 2: Gather Information Standard Parameters: the same for all chemicals, regardless of hazard Hazard Information: intrinsic information for each substance based on pre-defined health and environment end points Exposure Information: unique to each application / use and each company. Based on exposure categories and dependent on use Hazard information Exposure information Standard parameters Other available information

8 STEP 2: Gather Information Standard Parameters Parameter Chemical Identity and use : Classification and labeling information : Physical-Chemical Properties : Environmental Fate : Environmental Toxicology : Mammalian Toxicology : Description - CAS Number, Name, Structural Formula, Composition of the chemical, Use Pattern, Sources of Exposure, Route of Exposure - Physical hazard, Health hazard, Environmental hazard - Physical State, Melting Point, Boiling Point, Relative Density, Vapour Pressure, Co-efficient n-octanol/water, Water Solubility, Ignition Temperature - Aerobic biodegradability - Acute Toxicity (fish or daphnia) - Acute Toxicity

9 STEP 2: Gather Information Hazard Information Hazard Type Human Health Environment Physical-chemical hazards Endpoints - Acute toxicity (skin / oral / inhalation) - Eye / Skin irritation and corrosivity - Sensitization - Mutagenicity / Carcinogenicity - Repeated dose (skin / oral / inhalation) - Reproductive or Developmental toxicity (skin / oral / inhalation) - Acute toxicity - Chronic toxicity - Persistence - Bioaccumulation - Flammability (GHS classification) - Reactivity

10 STEP 2: Gather Information Exposure Information In addition to the standard parameters, gather any other available information (in house and online) on the human and/or environmental exposure scenario. Exposure Condition Product Characteristics : Product uses : Operational Conditions and Risk Management Measures : Environmental Characteristics : Information e.g. volume used in different sectors, packaging e.g. transported isolated intermediate used/stored off site; chemical included into or onto a matrix, nondispersive use, professional industry point sources, wide dispersive use e.g. process conditions protective equipment, ventilation, typical handling e.g. surrounding environment, waste water treatment

11 STEP 2: Gather Information Exposure Information Evaluate the quality of the information Whenever possible, always favor high-quality information sources. Certain sources of information are more favorable than others in terms of quality, reliability, relevance and accuracy of findings. Systematic approach to determining data quality (Klimisch et al.) 1. Reliable without restrictions: e.g. OECD guideline protocols 2. Reliable with restrictions: do not totally comply with guideline, but are sufficient to accept the data 3. Not reliable: e.g. non-physiological pathways of application 4. Not assignable: insufficient experimental details, short abstracts

12 STEP 3: Allocate substances into Tier In Step 3 you will: 1. Identify if your chemical has intrinsic hazard 2. Identify use, dissemination and exposure control of the chemical 3. Allocate chemicals into Tiers Hazard (Toxicity) Exposure High Medium Low Very Low High Tier 1 Medium Low Very Low Tier 4 Tier categorization Prioritization

13 STEP 3: Allocate substances into Tier Tier system and prioritization The GPS Tier system is based on a hazard / exposure rating. Progressively higher mammalian and environmental toxicological data requirements, are needed, depending the chemicals hazard and exposure potential. Tiers 1 and 2 : Substances with high to medium hazard and / or exposure potential are allocated to Tiers 1 and 2 for priority assessment. Tiers 3 and 4 : Substances with low to very low hazard and / or exposure potential are allocated to Tiers 3 and 4 for low priority risk assessment. Tier categorization is an efficient way of deciding which chemicals should undergo risk assessment in priority - but does not indicate the level of risk

14 STEP 3: Allocate substances into Tier Hazard assessment : identification of intrinsic hazard Exposure assessment : identification of use, dissemination and exposure control Allocation of substances into Tiers

15 STEP 3: Allocate substances into Tier Identify intrinsic hazard Check your substance against the criteria. Criteria is consistent with the United Nations Globally Harmonized System (GHS) and uses basic information on hazard endpoint toxicity values in order to help the user identify the intrinsic hazard of the substance. Hazard information (Standard parameters) (Other available information) Does Chemical have intrinsic hazard? Hazard level?

16 STEP 3: Allocate substances into Tier Identify intrinsic hazard Physical Hazards Identify intrinsic hazard Health Hazards

17 STEP 3: Allocate substances into Tier Identify intrinsic hazard Health Hazards

18 STEP 3: Allocate substances into Tier Identify intrinsic hazard Health Hazards

19 STEP 3: Allocate substances into Tier Identify intrinsic hazard Health Hazards

20 STEP 3: Allocate substances into Tier Identify intrinsic hazard Health Hazards

21 STEP 3: Allocate substances into Tier Identify intrinsic hazard Environmental Hazards

22 STEP 3: Allocate substances into Tier Identify intrinsic hazard - Decision tree Hazard information (Standard + Other available information) Does Chemical have intrinsic hazard? Hazard High Hazard Medium Hazard Low Hazard Very low Yes route Exposure assessment No route Exposure assessment

23 STEP 3: Allocate substances into Tier Identify use, dissemination and exposure control The potential for exposure depends on the use of the chemical (e.g. processing, formulation, mixing, filling, and production of a consumer product) which could lead to human or environmental exposure. Exposure information (Standard parameters) (Other available information) Setting exposure scenario? Exposure level?

24 STEP 3: Allocate substances into Tier Identify use, dissemination and exposure control Wide / Dispersive Limited Exposure Level Uncontrolled (High/Level 1) Controlled (Medium/Level 2) Controlled (Low/Level 3) Strictly controlled (Very Low/Level 4) Use Description - Worker / Consumer - Consumer use (assume exposure) - Environment - Professional/Consumer use (Emission of substances: Intentional) - Worker / Consumer - Professional use (e.g. By craftsman) - Environment - Professional/Consumer use (Emission of substances: Not intended) - Worker / Consumer - Industrial use - Environment - Industrial operations - Worker / Consumer - Closed-system process - Environment - Industrial operations (closed/strictlycontrolled System)

25 STEP 3: Allocate substances into Tier Identify use, dissemination and exposure control

26 STEP 3: Allocate substances into Tier Identify use, dissemination and exposure control - Decision tree From hazard identification Yes route No route Wide and dispersive industrial, professional or end-consumer use Limited industrial / professional use Wide and dispersive industrial, professional or endconsumer use Strictly controlled Yes No Tier 1 Tier 2 Tier 3 Tier 2 Tier 4

27 STEP 3: Allocate substances into Tier Allocate chemicals into Tiers for priority In order to prioritize the order in which your chemicals will be assessed for risk. The Tier-allocation also defines the appropriate level of information needed to be able to undertake further risk assessment. Tier Category Tier 1 Tier 2 Tier 3 - Top priority - 2nd priority - 3rd priority Priority Tier 4 - Lowest priority (No further action needed) (Only further action required is to assess the acute toxicity potential of the chemical in case of accidental exposure)

28 STEP 4: Develop Tier-specific Information Identify use, dissemination and exposure control In Step 4 you will: Gather Tier-specific information: in order to conduct a risk assessment on each chemical according to its Tier allocation Hazard and Exposure information (Standard parameters + Other available information) (Tier allocation) Tier 1 Tier 2 Tier 3 Tier 4 (Tier-specific information) Tier 1- specific Tier 2- specific Tier 3- specific Tier 4- specific

29 STEP 4: Develop Tier-specific Information

30 STEP 4: Develop Tier-specific Information

31 Tier-allocation with hazard & exposure levels An important concept of this section is the prioritization of chemicals into Tiers according to an initial consideration of their hazard and / or exposure potential. Tier-allocation with worst-case condition of hazard and exposure levels Exposure Level Wide / Dispersive Limited Uncontrolled (High) Controlled (Medium) Controlled (Low) Strictly controlled (Very low) Hazard (Toxicity) Level High Medium Low Very low Tier 1 Tier 1 Tier 2 Tier 2 Tier 1 Tier 1 Tier 2 Tier 2 Tier 2 Tier 2 Tier 4 Tier 4 Tier 3 Tier 3 Tier 4 Tier 4

32 Preparation (Step 1 to 4) - Summary By following the four steps in Section One, you prepared the ground for the implementation of the GPS risk assessment. Gathered Base Set Tier: (base set of information on hazard and exposure) Gathered all available hazard and exposure information (Standard parameters + Other available information) Categorized your chemicals according to the Tier allocation Prioritized your chemicals for risk assessment Developed further information, according to the Tier-categorization (Tier-specific information) Further Refine Risk Assessment (with more realistic condition)

33 Example : Formaldehyde 37% solution Classification according to GHS SDS

34 Example : Formaldehyde 37% solution Hazard Endpoint GHS Hazard Category Hazardous Level High Medium Low Very Low Flammable Liquid Category 3 X Acute Toxicity (oral) Category 3 X Acute Toxicity (inhalation) Category 3 X Acute Toxicity (dermal) Category 3 X Skin Corrosion/Irritation Skin Irritation Category 2 X Serious Eye Damage/Eye Irritation Category 1 Respiratory Sensitization Category 1 X Skin Sensitization Category 1 X Carcinogenicity Category 2 X Specific Target Organ Toxicity Single exposure Category 1 Aquatic Hazard - Acute Category 3 X X Hazard Level = High

35 Example : Formaldehyde 37% solution Identify use, dissemination and exposure control Exposure Type Worker Description, Use Descriptor Industrial use: Processes look poorly controlled Local Exhaust Ventilation (LEV) poorly positioned Poor housekeeping Visible surface contamination Low technology work practices Exposure Level High Medium Low Very low X Exposure Level = Wide / Dispersive

36 Step 5: Hazard Characterization - General principles A chemical s potential to cause toxic or adverse effects is known as intrinsic hazard. Hazard characterization is the process of determining if exposure to a chemical can cause adverse effects Because some hazard effects are limited to the tested animal species, hazard characterization also determines whether the adverse effect is likely to occur in humans. However, a chemical s intrinsic hazard will only manifest as an adverse effect if and when a set of conditions are met (a certain level of exposure, threshold of effect, incorrect handling and use).

37 Considerations when analyzing hazard data The endpoints in the hazard assessment are interrelated Degradation products and metabolites should be considered The appropriate route of exposure for toxicity testing should be selected (oral, dermal, inhalation, etc.) Test System Sensitivity (effect level depends upon the sensitivity of the test system) Dose-response (the relationship between the amount of exposure and its health effects) Identification of critical data (key studies) Select appropriate dose descriptors (e.g., NOAEL, NOEL, BMD, LD 50, LC 50, and T 25 )

38 Choose Most Relevant Route of Human Exposure Ingestion (water and food) Absorption (through skin) Inhalation (air) Injection (bite, puncture, or cut)

39 The Dose Makes the Poison An apparently nontoxic chemical can be toxic at high doses. (Too much of a good thing can be bad). Highly toxic chemicals can be life saving when given in appropriate doses. (Poisons are not harmful at a sufficiently low dose). Source: CHRIP, NITE, Japan

40 Dose-Response Relationship: The Degree and Spectra of Responses» depend upon the dose and the organism Change from Normal State» could be on the molecular, cellular, organ, or organism level--the symptoms Local vs. Systemic Reversible vs. Irreversible Immediate vs. Delayed Graded vs. Quantitative» degrees of the same damage vs. all or none Source: CHRIP, NITE, Japan

41 The Hazard Characterization Process Two main approaches - both follow the same basic methodology - however, the ways the outcomes presented are different: MOS/MOE: The classical approach is the derivation of a Margin of Safety (MOS), also termed Margin of Exposure (MOE). Here, assessment factors are considered after deriving the result. DNEL: In Europe, REACH legislation has established the Derived No Effect Level (DNEL). Assessment factors are accounted for in the process of the DNEL derivation and therefore are included in the result.

42 The Hazard Characterization Process Chemicals Policy and Health (CP&H)

43 1. Identify dose descriptors for each endpoint Identify dose descriptors for each relevant hazard endpoint (e.g. NOAEL, NOAEC, BMD, LD 50, LC 50, T 25 ).»e.g. NOAELs are derived from sub-acute, sub-chronic, chronic and reproductive toxicity tests they cannot be derived from acute, irritation or skin sensitization tests.»noael is the highest dose or concentration of the substance used, at which no statistically significant adverse effects were observed. For example if the dose levels of 400, 100, 50 and 5 mg/kg/ day have been used, and adverse effects were observed at 400, 100 and 50 mg/kg but not at 5 mg/kg, the derived NOAEL will be 5 mg/kg / day.

44 2. Modify the dose descriptor to the correct point of departure (POD) In certain situations, the dose descriptor may not be directly comparable to the exposure assessment e.g.» interspecies differences in bioavailability between experimental animals and humans;»the animal dose descriptor might relate to a different exposure route than the human exposure - requiring route-to-route extrapolation;»differences in human and experimental exposure time conditions; or»differences in respiratory volumes between experimental animals and humans. In these situations, it is necessary to modify the dose descriptor (e.g. NOAEL) into an appropriate Point of Departure (POD)

45 3. Decide on Mode of Action (threshold yes / no) Certain chemicals are thought to impose e.g. a carcinogenic risk without a threshold dose. For these chemicals the conventional NOAEL and DNEL derivation is not appropriate. The DMEL (derived minimal exposure level) describes the exposure level corresponding to a certain low risk, that appears to be tolerable though it is higher than zero. However, for carcinogens and mutagens workplace exposures should be avoided / minimized as far as technically feasible.

46 4. Apply Assessment Factor (AF) to the POD Uncertainties in the extrapolation of experimental animal test data to real human exposures are addressed by applying Assessment Factors (AF).»Difference in exposure duration between the experimental data and the assumed real-life exposure for humans;»route of exposure if different for humans»differences in sensitivity of response between species (inter-species) and within species (intra-species). After identifying the relevant individual assessment factors, the overall assessment factor is obtained by simple multiplication of the individual AFs.

47 5. Derive endpoint-specific DNEL To derive endpoint-specific DNEL(s) - the overall AF is to be applied directly to the POD Data from more than one valid and relevant studies may be available (e.g. in different species, with different durations), identifying more than one dose descriptor to a given endpoint. It might be necessary to derive DNELs for more than one dose descriptor, prior to selecting the lowest DNEL for that endpoint.

48 6. Select leading health effects After deriving your endpoint-specific DNEL or DMEL, select the leading health effect(s) and the corresponding DNEL/DMEL. These critical DN/MELs should be the lowest DN/MEL obtained for each exposure pattern. They will be used to characterize risk in the next step

49 Examples for DNEL calculation Step 1: Identify dose descriptor» Dermal Irritation (local effect) Dose descriptor: NOAEL 50 mg/kg bw/ day Rationale for selection of dose descriptor: Skin irritation observed at higher doses»adrenal gland changes (systemic effect) Dose descriptor: NOAEL 10 mg/kg bw/day Rationale for selection of dose descriptor: Adverse changes to adrenal glands observed at higher doses»developmental effects (systemic effect) Dose descriptor: NOAEL 50 mg/kg bw/day Rationale for selection of dose descriptor: Developmental effects observed at higher doses

50 Examples for DNEL calculation Step 2: Decide on threshold / non-threshold (Mode of Action)»Dermal Route, Local & Systemic Effects Irritation - Dose-response information supports threshold Adrenal - Dose-response information supports threshold Developmental - Dose-response information supports threshold

51 Examples for DNEL calculation Step 3: Modify Point of Departure»Irritation (Local) No modification needed»adrenal (Systemic) Effects Substance-specific data indicates dermal absorption is 2x less in humans than rats»developmental Systemic) Effects Substance-specific data indicates dermal absorption is 2x less in humans than rats

52 Examples for DNEL calculation Step 4 / 5: Apply assessment factors and derive DNEL Step 6: Select leading adverse effect» The DNEL-dermal-long term-local is 1.7 mg/kg bw/day» The DNEL-dermal-long term-systemic is 0.1 mg/kg bw/day

53 Environmental hazard characterization Environmental hazard characterization is conducted in a similar manner as for human health.»here PNECs (predicted no effect concentration) are used as dose descriptors and derived from the data collected. PNECs usually result from single species laboratory toxicity tests (e.g. fish, algae, and daphnia). Data are typically reported as the concentrations at which x% (e.g. 50%) mortality or inhibition of function (e.g. growth) is observed. PNECs are expressed as the lethal concentration (LCx) or the effect concentration (ECx), e.g. LC 50 or EC 50. A PNEC must be calculated for each environmental compartment in which exposure is expected (air, water, sediment and soil).

54 Sound Chemicals Management is a Global Responsibility. Questions and Answers By Mr. Krittanon Yuen-ying (Product Regulatory) Dow Chemical Thailand Limited krittanon.yuen-ying@dow.com Responsible Care Management Committee of Thailand Chemical Industry Club, The Federation of Thai Industries 6 June 2014, Bangkok, Thailand