Sampling

1
Sampling

• Thoughts on Sampling
• Ian Salomon
• Occ. Hygiene Officer
• W.C.B.

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Sampling

• So .......................
• you think you want to sample?

3
Sampling

• So .......................
• you think you want to sample?
• WHY?

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Sampling

• To monitor exposure
• To identify a contaminant
• To confirm there is a problem
• To confirm there is not a problem
• To review exposure for a claim

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Sampling

• Before you start, decide WHY you are going to do
  this.
• You can not do everything at one time just one.

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Sampling review exposure

• Do you need to be extremely accurate,
  or
• How about
• No problem,
• Hmmm,
• Oh Hell.

7
Sampling identify

• Lots of prep work
• listen to complaints
• review MSDSs
• survey work processes
• survey other businesses

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Sampling identify

• Now ................
• you can set a sampling strategy to identify one
  or more specific air contaminants.

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Sampling confirm a problem

• This one is easy!
• If you know the contaminant, and
• you know that there is a problem
• (by odour or people getting sick),
• then work out your strategy!

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Sampling confirm no problem

• Many contaminants can be smelled at
  concentrations far below hazard levels, so
• discuss and educate
• sample, if necessary

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Sampling confirm no problem

• Styrene 50 ppm 0.02 ppm
• Naphthalene
• 10 ppm 0.3 ppm
• Mercaptans
• 0.5 ppm 0.02 ppm

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Sampling

• Strategy
• What is the sampling method?
• What is the collection medium?
• What is the minimum sample volume
• Will this method give you an answer
• How many samples to collect?

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Sampling - Methods

• Filter
• Absorbent tube
• Impinger
• Swab/Wipe
• Cylinder
• Passive dosimeter
• Direct reading indicator tube or
  instrument

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Sampling

• Minimum sample volume is based on
• Detection limit of the analytical method,
• Exposure limit

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Sampling

• What to do if the sampling method and analysis
  leads to a negative result
• e.g. formaldehyde lt0.1 ppm
• EL is 0.3 ppm, but in an office, contaminants
  must be less than 10 of the EL (i.e. 0.03 ppm)

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Sampling

• Confidence limits
• Exposure monitoring
• Worst case sampling

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Sampling

• Personal or area samples?

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Sampling

• Personal samples
• Preferred
• Statistical validity 6 to 10 samples
• from similarly exposed persons
• Breathing Zone

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Sampling

• Area samples
• Much easier
• Locate source of emission
• May be used to estimate personal exposure
  (impinger methods), but will likely UNDERestimate
  the actual exposure.

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Sampling

• Contaminant Forms
• Dust, mist, fume
• Gas or vapour,

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Sampling

• Solid contaminants are filtered from the air
  sample.
• Gaseous contaminants are absorbed, adsorbed or
  dissolved.

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Sampling

• Sample Period must be consistent with exposure
  limit
• 8-hour, 15-minute, Ceiling
• Full period single sample
• Full period consecutive samples
• Partial period consecutive samples (70)
• Random (grab) samples

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Sampling

• Calibrate, calibrate, calibrate
• Start and finish

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Sampling

• Conundra
• Open-face or closed-face
• Lunchtime?
• Confidence limits

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Sampling

• Direct reading instrumentation
• Indicator tubes benefits and flaws
• Data-logging monitors

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Sampling I.A.Q.

• Q-Trax
• Monitor for CO2
• Check ambient
• Check work areas ambient 300
• ambient 650
• Check for air flow/ distribution
• Check temperature and humidity

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Sampling

• Th..Th..Thats all, Folks