Reprinted from the ACJ - January, 1995
Ah! Definitely domestic vintage, good ambiance, smell is fruity but not too tart, appears to have good body and excellent mouthfeel. I would guess it's a 1964 Corvette, or possibly a '65 GTO. If you work long enough in an auto repair garage, exhaust gases become like fine wine. You savor the subtle nuances, delight in the robust aroma, enjoy the dizzy buzz (but not so much the ensuing headache).
With garage doors closed tight against the cold, the problem of excessive automobile exhaust can become a hazard. The makeup of auto exhaust is truly a miasma of nasty constituents. Kind of like the old "Wapatooli" punch we used to make at college parties. Everyone brings a pint of something volatile and you throw it all together in a trash can half filled with fruit punch. CAUTION: We were trained professionals. Do not try this at home.
Like exhaust, the resulting brew seemed harmless enough. But realize that none of us graduated with higher than a "C" average. So let's see how you can avoid the nasty elements and effects of automobile exhaust in your shop. A mind is a terrible thing to waste.
The majority of car exhaust fumes are made up of carbon monoxide (CO), carbon dioxide (CO2) and incompletely burned hydrocarbons. Additives in the gas, and catalytic conversion, add sulfides and nitrous oxides (NOX) to the stew.
When we hear of someone being overcome by exhaust fumes, be it intentionally or just sitting in traffic with the windows rolled up, it is reported that they suffer from, or died of, carbon monoxide poisoning. Efficiency is the only reason for CO's popularity, for any number of exhaust gas constituents could cause illness or death. It is just that CO beats them to the punch … I remember that guy in school who always beat us to the punch … sorry, I was just reminiscing.
CO is classed as a poison by the inhalation route. It can replace the oxygen in our blood and slowly suffocate our body. This effect can be deadly, but the good news is that the half-life, or the time it takes for our body to rid itself of half of the material, is just over an hour. So if a person is removed from the contaminated area, within one or two hours all detrimental effects — dizziness, nausea, etc. — should pass.
However, the chronic effects of periodic low concentration dosing will remain to cause you problems. Vision restriction, heart irregularities and mental/nervous system damage can all occur over time.
Carbon Dioxide is also present in exhaust gases as it is in normal air, though at an increased concentration. Even this relatively safe gas can cause problems if the concentration is high enough to displace oxygen in the room, causing slow asphyxiation.
Oxides of nitrogen, NO and NO2, make up a portion of automobile exhaust and can cause health problems. Both NO and NO2 are listed as "deadly" poisons when breathed. They just take their time in killing you, whereas CO hustles to the task. Both are skin, eye and mucous membrane irritants. Pulmonary (lung) inhibition can occur over time with repeated NOX doses. NO2 has also been found to cause mutations in living cell tissue.
Now here is the scary part: All of these harmful gases we have mentioned are colorless and odorless and therefore can harm us without warning. Thank goodness that auto exhaust also harbors a large majority of stinky, partially burned hydrocarbons. These hydrocarbons have the distinctive petroleum smell associated with exhaust gas. It helps warn us of the other more harmful gases that will be present.
These hydrocarbons are not the little angels they seem to be. As with all carbon based non-aqueous molecules, our bodies cannot process them well and they are suspected of causing various forms of cancer in laboratory animals. But at least they warn us of their presence.
Another characteristic smell associated with catalytic converter exhaust is that of sulfur. Actually, the smell is caused by any number of sulfides that form in the catalytic process. Lead in the exhaust fumes is certainly not the big concern it used to be before unleaded gas, but remember that leaded gas means lead in the exhaust, complete with all the fun ailments and raised blood lead readings associated with lead solder fumes.
It should be apparent that I have spent quite some time explaining the hazards of exhaust gases. This is because my advice on how to avoid these hazards will be pitifully short. Keep the shop well ventilated and don't allow cars to run in the shop unless they are hooked up to a vent system. And if the shop does fill up with exhaust, bite the heating bill bullet and open the doors for a time to provide a complete shop air exchange.
The diversity of harmful components in automobile exhaust make it difficult to protect yourself with any type of respirator short of a supplied air system. No one cartridge can adequately filter out all the nasties. So the best protection is to keep the fumes from accumulating.
Now as you head back to work, keep in mind that with exhaust fumes, as with fine wine, we may enjoy its company from time to time, but suck down enough of it and you will get a nasty headache and hangover. So like that freshly opened bottle of wine, allow your shop, and yourself, to breathe.
By the way, I won a bet by not making a single tasteless joke about certain gases not associated with the automobile. So go ahead, talk amongst yourselves.
The above article was written by David M. Brown, Chief Engineer of Johnson Manufacturing Company, Inc. and is published by JOHNSON with the expressed approval of the National Automotive Radiator Service Association and the Automotive Cooling Journal. Other reproduction or distribution of this information is forbidden without the written consent of JOHNSON and NARSA/ACJ. All rights reserved.
JOHNSON MANUFACTURING COMPANY
114 Lost Grove Road / PO Box 96 / Princeton, Iowa 52768-0096
Phone 563-289-5123 or Fax 563-289-3825