Post on 04-Jan-2016
VOC’s/CFC’s and Ozone
Dan Gloudemans
Presentation Overview
VOC’s Ozone
Formation, natural/other VOC’s
Destruction, natural/other CFC’s
Measurement / EPA AQI Ozone hole/ Home Ozone exposure What is being done about Ozone?
Clean Air Act OTC CARB/OTC
Ozone in the Midwest?
Brief VOC overview
Organic Compound – contains carbon and hydrogen Ie: octane, butane…, sugar
VOC = Volatile Organic Compound, organics that evaporate easily
VOC’s are compounds that lead to the formation of ground level Ozone – “smog”
VOC’s can be found in anything from paints to deodorant
Good/Bad Ozone – “Good up high, bad nearby”
Ozone is beneficial in Stratosphere blocks many ultra violet rays (λ < 320 nm)
But is very harmful in Troposphere it is a highly reactive gas that can affect the normal
functioning of the lungs
Formation of Ozone (O3) “natural”
Ozone first formed - ~500 million years ago, after release of Oxygen
Ozone formation – atomic Oxygen Most natural ozone formation occurs in the Tropics
“Chapman reactions” So called after S. Chapman who is famous for his paper 'A theory of upper-atmosphere ozone, Mem. Roy. Meteorol. Soc.' in 1930 which set out the first theoretical explanation of the ozone layer in the stratosphere.
…Other formation of Ozone - Groundlevel
Photochemical reaction of NOx (collectively NO and NO2) with VOC’s in the presence of sunlight
Destruction of Ozone - “natural”
Ozone destruction by UV radiation – very similar fashion
Ozone concentration highest in the poles!
…Other Destruction of Ozone
CFC’s among others Organic molecules – H’s replaced with Halogens Cl
and F
Measurement of Ozone
Reported in Dobson Units (DU)
Imagine all ozone on the surface of the earth evenly (vs. reality of the strato/troposhpere)
1 DU = 0.01 mm of Ozone 300 DU a typical value Thus, 300 DU = 3 mm O3
spread evenly across earth
AQI – Air Quality Index
Measures presence of 5 pollutants ground-level ozone particle pollution carbon monoxide sulfur dioxide nitrogen dioxide
0-500 Scale 100 is National Air quality standard ~200 – unhealthy to very unhealty – whole
population could be affected >300 - Hazardous
The “Ozone Hole”
Over Antarctica First noticed in 1970’s
British Antarctic Survey (BAS) First discovered/measured in
1985 TOMS (Total Ozone Mapping Spectrometer).
Findings thought faulty Eventually confirmed Graph shows measurements
above the Halley Bay research station
Home Exposure to VOC’s
EPA's Total Exposure Assessment Methodology (TEAM)
Found that VOC level are often 2 to 5 times higher indoors
The relative danger varies greatly Length and level of exposure
nose and throat discomfort, headache, allergic skin reaction, nausea, fatigue, dizziness.
What is being done about Ozone?
US adopted Montreal Protocol in 1987 – limit CFC’s States most dangerous phased out by 2000
Clean Air Act All class I substances outlawed by Jan 1 2000
chlorofluorocarbon-11 (CFC–11) chlorofluorocarbon-12 (CFC–12) + others
All class II substances outlawed by Jan 1 2030 hydrochlorofluorocarbon-21 + various other
Ozone “Action Days” Days > 90F, little or no wind Encourage to reduce emmisions, and protect
OTC – Regional effort
OTC = Ozone Transport Commission Several northeastern states (13 total) Created under Clean Air Act (CAA) amendments
in 1990 Focus on Ground Level Ozone - specifically NOx
emissions - during May – Sept “Ozone Season” NOx Budget Program – sell or store unused
allowances Regional emissions trading program
OTC - Progress
OTC – but room for More progress
CARB/OTC
California Air Resource Board In addition to NOx, these two regulate VOC
emmisions Consumer Products
Wisconsin Ozone?
Yes! Southeastern Wisconsin During Action Days
Combining errands Fueling car gas tanks at night Mowing lawns after 6:00 p.m Properly inflating vehicle tires Carpooling, biking, walking or riding the bus to
work
Midwestern Ozone problem areas
US EPA, Region 5
What about Minnesota?
Questions?
References
• EPA – “air Now”• How VOCs Contribute To Formation Of Ground-Level Ozone. Chemical
& Engineering News, 1/24/2005, Vol. 83 Issue 4, p26, 1/3p; (AN 16120478)
• Chemical & Engineering News; 1/24/2005, Vol. 83 Issue 4, p25, 3p, 1c “SMOG, POLICY AND CHEMISTRY.”
• http://www.dnr.state.wi.us/org/aw/air/ozone/OzActionNotice.htm