# Is it safe to drink D2O?
**URL:** https://boards.straightdope.com/t/is-it-safe-to-drink-d2o/83024
**Category:** Factual Questions
**Created:** [September 21, 2001, 3:17pm UTC](https://boards.straightdope.com/t/is-it-safe-to-drink-d2o/83024 "2001-09-21T15:17:53Z")
**Posts on this page:** 3
**Page:** 2
### Author:  [@astro](https://boards.straightdope.com/u/astro)
#### Post date: [September 23, 2001, 5:55am UTC](https://boards.straightdope.com/t/is-it-safe-to-drink-d2o/83024/21 "2001-09-23T05:55:39Z")
No, depending on the spider you would either be
extremely annoyed man
[http://arachnophiliac.com/burrow/gallery/other/images/whip\_scorpion\_west\_indies\_close\_up.jpg](http://arachnophiliac.com/burrow/gallery/other/images/whip_scorpion_west_indies_close_up.jpg)
screaming man
[http://www.desertusa.com/july97/du\_bwindow.html](http://www.desertusa.com/july97/du_bwindow.html)
dead man
[http://www.powerup.com.au/~glen/spider3.htm](http://www.powerup.com.au/~glen/spider3.htm)
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### Author:  [@Andy](https://boards.straightdope.com/u/Andy)
#### Post date: [September 23, 2001, 10:23am UTC](https://boards.straightdope.com/t/is-it-safe-to-drink-d2o/83024/22 "2001-09-23T10:23:14Z")
Kinetic isotope effects (KIE) is defined as KIE=_k_[sub]H[/sub]/_k_[sub]D[/sub].
The theroretical maximum value of KIE is about 7 at room temperature for reactions where a bond to H or D is broken, hence the ability of deuteration to slow vital enzymic reactions significantly. Typical experimental values of between 1 and 2 are common.
If you consider the fact that the body goes to great lengths to maintain a constant temperature (which is a major factor in the rate of reactions), it becomes obvious why these apparently rather small changes in reaction rates can have dramatic effects.
I seem to recall reading that primary KIE’s had been observed of ca. 70, although I’m not sure what type of reaction this was from.
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### Author:  [@Another\_Primate](https://boards.straightdope.com/u/Another_Primate)
#### Post date: [September 23, 2001, 10:34am UTC](https://boards.straightdope.com/t/is-it-safe-to-drink-d2o/83024/23 "2001-09-23T10:34:13Z")
You folks are inspiring me to go to college. I love math, enjoyed chemistry, was offered a full ride to Harvey Mudd back in 1972, and decided to get married instead. (I’ll go back someday…)
Now I’m 47 and found myself feeling proud yesterday for figuring out a license plate: PB 2 AU.
Whoo-hoo!
Anyway, really interesting. Thanks!
-Sue
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