Community Air Pollution from Crash Repair Workshops

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Community Air Pollution from Crash Repair
Workshops

• Dino Pisaniello
• Department of Public Health
• Adelaide University, Australia

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• Background to the public health issue
• Aims and objectives of study
• Project design
• Proximity data
• Stack emission and ground level data
• Implications

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Isocyanate components of two-pack polyurethane
paints Associated with respiratory disease
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Community concerns about emissions from spray
painting workshops odours, potential toxic
effects etc. Australia has one of the highest
rates of asthma How significant is the issue?
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Objectives

• To identify all crash repair spray painting
  workshops in the Adelaide metropolitan area which
  use (two-pack) isocyanate paints.
• To determine and characterise, using descriptive
  statistics, the proximity of exhaust stacks to
  homes and offices.

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Objectives (cont.)

• To quantitatively determine, for a sample of
  workshops
• stack emissions of isocyanates and solvent
  vapours, with concurrent measurement of
  meteorological variables
• ground level concentrations of isocyanates and
  solvent vapours at various distances from the
  emission source
• To interpret the public health significance of
  the data by comparison with occupational and
  environmental air quality guidelines.

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Proximity Data n 131 Other other small
business, factories, shops etc.
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Methods

• Isocyanates (HDI and HDI oligomers)
• UK HSE MDHS 25/2
• using coated glass fibre filters and HPLC UV/EC
• isokinetic stack sampling
• Solvent vapours
• (toluene, xylenes, butyl acetate and MEK)
• charcoal sorbent tubes with GC/FID analysis
• Meteorological variables
• (wind speed, direction, temperature, humidity)
• MEA automatic weather station positioned on roof

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Observations

• Isocyanate spray time is relatively short (2-15
  of day)
• Some touch up painting work (usually non-two
  pack) done outside of booth
• There appears to be adequate plume dispersion
  the plume is seen to rise and disperse
• Workshops rarely use HVLP guns
• Charcoal filters noted for one workshop

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Stack Isocyanate Data Overall median 136 mg
NCO/m3 during spraying and 11 mg NCO/m3 as
a daily TWA
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Stack Solvent Concentrations During Spraying
Median mg/m3 Geometric mean mg/m3 Range mg/m3
Toluene 25 28 3 - 630
Xylene 52 43 3 - 402
Butyl acetate 70 44 0.3 - 523
MEK 2.6 1.2 0.1-12
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Interpretation Stack Monitoring
ISOCYANATES Data show isocyanate concentrations
to be several times the STEL while spraying is in
progress i.e. 70 mg NCO/m3 Will depend on the
proportion of hardener, isocyanate content of
hardener, gun type, shape and orientation of
object being sprayed, booth exhaust filtration
efficiency etc. SOLVENTS Total solvent
concentrations while spraying 100 - 1,000
mg/m3 These values approximate STELs
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Perimeter Samples
Isocyanates (HDI and HDI oligomers) Below the
limit of detection (approx. 0.05 mg NCO/m3)
Solvent vapours Below the limit of detection
(approx. 0.1 mg/m3) except for one sample where
work was done outside of booth3.6 mg/m3 for
toluene
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Conclusions

• Isocyanate emissions are at hazardous
  concentrations near the stack when spraying is
  occurring. However, isocyanate spray time is
  relatively short (2-15 of day)
• Ground level (perimeter) concentrations are very
  low
• There appears to be adequate plume dispersion
  the plume is seen to rise and disperse
• Solvent vapour concentrations at the stack are at
  marginally-hazardous levels
• Solvent vapours at ground level are very low, but
  there may be an odour depending on wind direction
• Work outside the booth may generate nuisance
  levels of solvent vapour
• The lowest concentration of isocyanates and
  solvents were found for a booth with a charcoal
  filter