# Why does freon smell like xylocaine tastes?

**URL:** <https://boards.straightdope.com/t/why-does-freon-smell-like-xylocaine-tastes/202088>\
**Category:** Factual Questions\
**Created:** [September 17, 2003, 4:22am UTC](https://boards.straightdope.com/t/why-does-freon-smell-like-xylocaine-tastes/202088 "2003-09-17T04:22:41Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\
**Post date:** [September 17, 2003, 4:22am UTC](https://boards.straightdope.com/t/why-does-freon-smell-like-xylocaine-tastes/202088/1 "2003-09-17T04:22:41Z")

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To make a long story really short I had some freon lines blow up very close to me yesterday, they then proceded to fog the entire room. Anyways I noticed right away that the freon smelled EXACTLY like what the dentist puts on your gums to numb them before giving novacaine IIRC they use xylocaine. Just being in the room made me feel like my tongue was going to go numb (could be psychological based on the smell, could be the connection between taste buds and olfactory nerves.) Anyways my questions are…Has anyone else noticed this (HVAC service persons)? Is there some chemical similarities that cause this? Would freon work as an anaestetic (sp?) either general or local? No real reasons for this question, it just got me thinking when it happened.

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**Author:** ![scm1001](https://avatars.discourse-cdn.com/v4/letter/s/c4cdca/32.png) [@scm1001](https://boards.straightdope.com/u/scm1001)\
**Post date:** [September 17, 2003, 10:38am UTC](https://boards.straightdope.com/t/why-does-freon-smell-like-xylocaine-tastes/202088/2 "2003-09-17T10:38:00Z")

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some fluorinated hydrocarbons are indeed used in anathesia, more information than you probably want on  
[http://exobiology.nasa.gov/ssx/biomod/papers990823/anesth3.15/anesth3.15.html](http://exobiology.nasa.gov/ssx/biomod/papers990823/anesth3.15/anesth3.15.html)  
[http://www.wowessays.com/dbase/af2/jai133.shtml](http://www.wowessays.com/dbase/af2/jai133.shtml)

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**Author:** ![spingears](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spingears](https://boards.straightdope.com/u/spingears)\
**Post date:** [September 17, 2003, 12:13pm UTC](https://boards.straightdope.com/t/why-does-freon-smell-like-xylocaine-tastes/202088/3 "2003-09-17T12:13:43Z")

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The senses of smell and taste are closely allied, so that a strong smell or taste recalls similar tastes or smells.