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Jacques Whitford Presentation. Introduction to Odour Emissions Review (NPRI) Particulate Emissions Noise Assessment February 21, 2007. What is Odour?. Odour is the sensation resulting from the stimulation of the olfactory organs
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Jacques Whitford Presentation • Introduction to Odour • Emissions Review (NPRI) • Particulate Emissions • Noise Assessment February 21, 2007
What is Odour? • Odour is the sensation resulting from the stimulation of the olfactory organs • An odorant is a substance capable of eliciting an olfactory response. • People associate odours with past experiences and involuntarily assess the odour as likable, dislikable or indifferent (e.g. – in a study by Iowa State University, children younger than 5 rated sweat and feces odours as likable, but above that age as unlikable).
Odour Response • The way the human response to an odour is evaluated, depends on the particular sensory property that is being measured, including: • Intensity (the strength of the perceived odour sensation), • Detectability (the minimum concentration that produces an olfactory response or sensation), • Character (property that identifies an odour and differentiates it from another odour of equal intensity), and • Hedonic tone (property of an odour relating to its pleasantness or unpleasantness ). • The combined effect of these properties is related to the annoyance that may be caused by the odour. • Human ability to perceive odour varies widely, as does individual responses to a specific odour.
Odour Quantification • Mixtures of compounds require dynamic olfactometry for assessment of odour level. • This involves exposing a selected and controlled panel of observers to precise variations in the concentrations in a controlled sequence, to determine the point at which only half the panel can detect the odour. • This point is called the odour threshold or one odour unit.
Odour in the Environment • VOC emissions are emitted from the stacks and are carried downwind. • The plume dilutes via entrainment of ambient air as it is carried downwind. • Residents downwind of the stacks are exposed to the diluted concentrations of the VOCs and may or may not detect the odour depending on the concentration and chemical.
National Pollutant Release Inventory (NPRI) Background • Nation-wide, facility specific, publicly accessible inventory • Inception in 1992. • Collects information about: On-site releases and disposal, off-site transfers for disposal and recycling, pollution prevention. • Substances to be reported has changed over the years. Reporting Criteria Threshold Determination: • Employee threshold (Number of employee hours) • Activity based (Some activities are exempt from the employee threshold) • MPO (Manufacture, Process or Otherwise Use) Threshold: varies by substance • Release Threshold: varies by substance • Concentration Threshold: varies by substance
Emissions - Summary • Raywal emissions did not jump substantially in 2002 – NPRI reporting criteria changed resulting in more emissions being reported. • Raywal emissions (total VOCs) have decreased slightly over the last three reporting years. • Raywal was about 1% of total VOC emissions in Markham in 2000-2002 (an approximate estimate).
Particulate Emissions • PM emissions from wood cutting, sanding, etc are controlled by pick-up points through the facility and vented to a baghouse. • The baghouse uses cloth filter bags to remove PM from the air stream. Baghouses typically have 99% or greater removal efficiencies. • The exhaust from the baghouse is vented back into the building – no external PM emissions. • In the spray booths, filters are used to removed paint droplets from overspray. These filters are typically about 95% efficient. • If paint droplets pass through the filters, they typically deposit in the stack or on the roof – a good indicator of poorly performing spray booth filters is paint around the top of the stack. This is not happening at Raywal.
