Consumer exposure scenarios under REACH

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Consumer exposure scenarios under REACH

• An update
• Cees de Heer / Jacqueline van Engelen

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Contents

• Consumer exposure assessment
• REACH Implementation Projects
• The latest proposals

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Consumer exposure

• Exposure Scenarios (ES)
• Use of a substance including RMMs
• Tiered/iterative exposure evaluation
• (RIP 3.2-2 chapter 15)
• Almost no difference with previous approach (new
  and existing chemicals)

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Exposure Assessment

• Tier 1
• screening, simple default equations
• picklist of product categories (under discussion)
• use default input values (under discussion)
• iterate by
• replacing default inputs with more
  appropriate/product specific data
• Equations listed in TGD
• Recommended tools ECETOC TRA (/ConsExpo)
• Tier 2 and higher tier
• more complex equations/tools
• recommended tool ConsExpo

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First Tier Equations

• Inhalation a
• Substance released at once into the air
• Dermal a
• instant application of a substance contained
  in a preparation
• Dermal b
• non-volatile substance migrating from an
  article
• Oral a
• unintentional swallowing of a substance in a
  product during normal use

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Exposure assessment

• Tier 1
• Recommended tools for tier 1 ECETOC TRA
  (/ConsExpo)
• Call from ECHA for construction of an IT tool to
  prepare the CSA/CSR (focussed on tier 1 exposure
  assessment)
• Tier 2 and higher tier
• more complex equations/tools
• recommended tool ConsExpo

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ECETOC TRA

• Report from 2005
• Before guidance
• Provides consumer categories
• Provides equations (different from new TGD)
• Tier 1 (idem)
• Provides default values
• Aggregates 3 routes

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ECETOC TRA
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ECETOC TRA example dermal exposure
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RIP3.2 Model Evaluation

• Comments RIP3.2 on ECETOC TRA
• Not tier 1 (but somewhere between 1 and 2)
• No justification for the defaults
• -gt Recommendation to use ConsExpo

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Response from ECETOC

• Meeting with MS
• Willing to change equations
• Willing to justify defaults
• Willing to separate equations for articles and
  preparations
• Meeting Helsinki April 10, June 6
• New proposal from ECETOC

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Comments June 2008

• Seems reasonable, but
• Assumption of a layer in combination with a
  migration factor
• Product use duration
• Exposure expressed over 1 day (dividing by 24),
• 0.2/24h gtfactor 100!
• No justification of defaults
• Still not tier 1, and no justification
• Agreed further justification of default values
  and sentinel product

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August 2008

• List of scenarios The following scenarios have
  been worked out by industry
• Air Fresheners (Spray air care)
• Artist supply and craft/hobby preparations
  children finger paints
• Coatings and paints, fillers, putties, thinners
  
• Fabrics, textiles and apparel (Article)
• Paintings and coatings (Short term exposures)
• Plastic products (Plastic toys) Article
• Soaps and detergents (washing cleaning agents)

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August 2008 proposal
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Main comments (RIVM/BfR)

• Scenarios are not generic
• Justification defaults not clear
• Sentinel product not worst case for category
• Choice of categories are not according to
  exposure characteristics (crayons, electrodes and
  glue)
• Combination layer and migration is not tier 1

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New proposal BfR/RIVM

• Simple scenarios (back to TGD)
• Limited number of pre-set defaults
• For each category a combination of the pre-sets
  will be proposed

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Dermal scenario

• A skin contact area is stated.
• From a thin layer of this area, all product
  ingredient is released at once.
• Dermal absorption is set at 100
• Algorithm
• Surrogate of exposure mg /(kg bw x day
• PI x CA x FQ x TL x D x 1000 /BW
• for each product use category
• Selectable / Fixed

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Variables dermal scenario

• PI (product ingredient) surrogate value for each
  product use category if fraction is unknown g/g
• CA (Skin contact area) cm2
• 8 pre-set values from fingertips through hands
  and underarms to whole body Skin contact area
  depends on body weight.
• FQ (Frequency of use) in events /day
• TL (Thickness of layer)
• 0.001 cm (fixed product ingredients)
• 0.01 cm (aqueous solutions, other solutions with
  the viscosity of water (thinners), non fixed
  materials (textiles), pastes and viscous
  materials, (paints, coatings fillers, putties,
  lubricants, greases)(Reference for aqueous
  solutions TGD, 2003)
• D (Density) 1 g/cm3
• BW (Body Weight) 10 kg (child) or 60 kg (adult)

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Oral scenario

• An oral contact area and the thickness of the
  contact layer are stated. From the thin layer of
  this area all product ingredient is released at
  once, and is swallowed.
• Alternatively, a volume of product which is
  swallowed can be stated (e.g. a peace of chalk)
• Oral absorption is set at 100
• Algorithm
• Surrogate of exposure mg /(kg bw x day
• PI x V x FQ x D x 1000 /BW
• for each product use category
• Selectable / Fixed

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Variables oral scenario

• PI (product ingredient) g/g
• V (volume product swallowed) CA x TL cm3
• CA (Oral contact area) cm2
• 4 preset values from some fingertips to one
  hand/all fingers or area product mouthed Skin
  contact area depends on body weight, default
  values in General Fact Sheet
• TL (Thickness of layer) 0.01 cm (fixed product
  ingredients)
• Instead of calculating a volume from CA and TL, a
  volume of product which is swallowed is directly
  stated
• FQ (Frequency of use) events /day
• D (Density) 1 g/cm3
• BW (Body Weight) 10 kg (child) or 60 kg (adult)

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Inhalation scenario

• Exposure during, and after use of the product, in
  a small room, without ventilation
• Sprays all aerosol particles can be inhaled,
  irrespective of the vapor pressure of the
  components.
• Surface evaporation depending on vapor pressure
• It is assumed that all compound in the thin upper
  layer evaporates immediately and is inhaled in
  the small room (without ventilation). Therefore
  this exposure covers not only the inhalation
  exposure, but also the dermal and oral exposure
  of compounds in house dust.
• Inhalation absorption is set at 100

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Inhalation scenario (2)

• Algorithms
• Surrogate of exposure mg/(kg bw x day
• PI x A x FQ x ET x IR x 1000 / V x BW
• for each product use category
• Surrogate of exposure mg/m3
• PI x A x 1000 / V
• for each product use category
• Selectable / Fixed

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Variables inhalation scenario

• PI (product ingredient) g/g
• A (amount of product)
• VP gt 0.1 Pa or if product is sprayed A g /
  event
• VP lt 0.1 Pa A S x TL x D g /event
• S (evaporating surface) cm2
• TL (thickness of layer, VP dependent) cm
• D (Density) 1 g/cm3
• FQ (Frequency of use) events /day
• ET (exposure time) hr
• IR (inhalation rate) m3/hr (depends on BW,
  light exercise)
• V (room volume) 20 m3
• BW (Body weight) 10 kg (child) or 60 kg (adult)

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Consumer product use categories

• Univocal products, categorisation according to
  exposure pattern
• Paints
• DIY products
• Cleaning products
• Fabrics, textiles and apparel
• Plastic products
• Paper products
• Lubricants, greases, fuel
• Wood and wood products
• Rubber products
• Leather products
• Miscellaneous

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DIY products

• Glues, hobby use
• Glues DIY-use (carpet glue, tile glue, wood
  parquet glue)
• Glue from spray
• Sealants
• Fillers and putty
• Plasters and equalizers
• Removers (paint-, glue-, wall paper-,
  sealant-remover)

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Cleaning products

• Laundry and dish washing products
• Cleaners, liquids (all purpose cleaners, sanitary
  products, floor cleaners, glass cleaners, carpet
  cleaners, metal cleaners )
• Cleaners, trigger sprays (all purpose cleaners,
  sanitary products, floor cleaners, glass
  cleaners)
• Polishes, wax / cream (floor, furniture, shoes)
• Polishes, spray (floor, furniture, shoes

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Complex articles

• The exposure of more complex articles, which
  consist of a number of different materials (e.g.
  rubber, plastic, metals), cannot be described for
  the whole article in one time.
• The exposure has to be assessed for the different
  parts of the article.

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Conclusions

• Work is still in progress
• Next meeting early November
• Agreement on approach and proposed
  pre-sets/default values foreseen end of this year
• Regular updating based on user experiences

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Acknowledgements

• Jan-Dirk te Biesebeek
• Harry Bremmer