# Carbon Monoxide poisoning from diesel? **URL:** \ **Category:** Factual Questions\ **Created:** [May 13, 2006, 11:02pm UTC](https://boards.straightdope.com/t/carbon-monoxide-poisoning-from-diesel/356681 "2006-05-13T23:02:41Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![LanceShetrompf](https://avatars.discourse-cdn.com/v4/letter/l/ba8739/32.png) [@LanceShetrompf](https://boards.straightdope.com/u/LanceShetrompf)\ **Post date:** [May 13, 2006, 11:02pm UTC](https://boards.straightdope.com/t/carbon-monoxide-poisoning-from-diesel/356681/1 "2006-05-13T23:02:41Z")
I work at a car dealership that has a diesel gas model. We were sitting behind one of the cars today and were talking about the new technology of the diesel engines. There was very little noise and no black smoke (EPA guidelines, you know). After talking, I said that we will still probably get sick from the carbon monoxide. A co-workers response was: you can’t get carbon monoxide poising from a diesel car. So my questions are as follows: Can you get carbon monoxide poisoning from the fumes of diesel gasoline? If not, does this mean it would be safe to sit in a garage with a diesel engine running? If not, why not? ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [May 14, 2006, 1:13am UTC](https://boards.straightdope.com/t/carbon-monoxide-poisoning-from-diesel/356681/2 "2006-05-14T01:13:09Z")
> [@LanceShetrompf](#): > > Can you get carbon monoxide poisoning from the fumes of diesel gasoline? [This site](http://www.coheadquarters.com/coautoetc1.htm) says that diesel engines typically emit only about 1% to 10% of the CO of a comparable gas engine (though a poorly maintained diesel engine may be substantially worse). Is that enough to cause trouble? Probably, given long enough exposure. > [@](#): > > does this mean it would be safe to sit in a garage with a diesel engine running? There’s more than CO to worry about. [Here](http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=36089)’s what the American Lung Association says: > [@](#): > > Diesel exhaust is a mixture containing over 450 different components, including vapors and fine particles. Over 40 chemicals in diesel exhaust are considered toxic air contaminants by the State of California. Exposure to this mixture may result in cancer, exacerbation of asthma, and other health problems. Of course, they aren’t saying how long you must be exposed before you can expect those problems. ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [May 14, 2006, 1:14am UTC](https://boards.straightdope.com/t/carbon-monoxide-poisoning-from-diesel/356681/3 "2006-05-14T01:14:47Z")
Carbon monoxide is a result of incomplete combustion. A deisel engine is a combustion engine therefore it will produce a small amount of carbon monoxide. I have no idea if that ratio goes up or down between deisel and regular fuel, but I can pretty much garantee that it is not safe to sit in the garage with your deisel engine running. ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [May 14, 2006, 2:34pm UTC](https://boards.straightdope.com/t/carbon-monoxide-poisoning-from-diesel/356681/4 "2006-05-14T14:34:06Z")
> [@Christopher](#): > > Carbon monoxide is a result of incomplete combustion. A deisel engine is a combustion engine therefore it will produce a small amount of carbon monoxide. I have no idea if that ratio goes up or down between deisel and regular fuel, but I can pretty much garantee that it is not safe to sit in the garage with your deisel engine running. Slight Clarification: “Incomplete combustion” is synonymous with “inefficient combustion”. Like everything else in this world, you can never achieve 100% perfect combustion. As a result, there will always be CO in the bi-products of combustion. {Some may have seen a chemical formula written for the combustion of octane (C8H18) for example, there is (a) an ideal formula, i.e.: without CO, and (b) an incomplete formula with CO. In any case, this is the overall chemical formula which is really a series of smaller, intermediate reactions.) - Jinx ---
**Author:** ![Kevbo](https://avatars.discourse-cdn.com/v4/letter/k/e47774/32.png) [@Kevbo](https://boards.straightdope.com/u/Kevbo)\ **Post date:** [May 14, 2006, 11:03pm UTC](https://boards.straightdope.com/t/carbon-monoxide-poisoning-from-diesel/356681/5 "2006-05-14T23:03:18Z")
> [@Christopher](#): > > Carbon monoxide is a result of incomplete combustion. That is a true statement. Consider, however, that you are starting with a Hydrocarbon molicule. If it combusts to the point of forming CO, then it has started to burn. The major way in which combustion can be stopped at that point is through a lack of available oxygen. Diesels are designed to over supply oxygen (lean burn) under all conditions. (barring hop-up modifications, poor maintainance, malfunctions, etc.) Thus the CO production is almost nil. There is a very small amount, as the other way of putting out the fire (cooling) is possible, but specifically minimized in the design process. To elaborate, the injector spray pattern is shaped to avoid fuel impinging on the piston top or cylinder wall. This is specifically determined in the design testing phase by looking for CO in the exhaust stream. If CO is detected, injection rate, timing, or injector spray pattern is altered to minimize it. Having lots of extra air does provide lots of nitrogen and left-over oxygen, so diesels tend to have issues with NOx levels rather than CO.