# Industrial Breathing **URL:** \ **Category:** Factual Questions\ **Created:** [March 7, 2003, 11:10pm UTC](https://boards.straightdope.com/t/industrial-breathing/159813 "2003-03-07T23:10:49Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![i3igpete](https://avatars.discourse-cdn.com/v4/letter/i/c6cbf5/32.png) [@i3igpete](https://boards.straightdope.com/u/i3igpete)\ **Post date:** [March 7, 2003, 11:10pm UTC](https://boards.straightdope.com/t/industrial-breathing/159813/1 "2003-03-07T23:10:49Z")
i was wondering if it’s safe to breathe the oxygen tanks you find in hardware stores. the reason i ask is that when you see stores that sell oxygen cylinders for medical supply companies, they dont come filled and they always say you can fill them for $5. i’m assuming that for such a cheap price, it has to be the same place that would fill tanks that would be used in welding. aside from that, let’s say they are safe to breathe. what health problems would i see besides nausea, passing out, and pneumonia? ---
**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\ **Post date:** [March 8, 2003, 3:59pm UTC](https://boards.straightdope.com/t/industrial-breathing/159813/2 "2003-03-08T15:59:20Z")
[http://yarchive.net/med/oxygen\_lung\_damage.html](http://yarchive.net/med/oxygen_lung_damage.html) > [@](#): > > Q: Is there harmful effects from breathing pure oxygen? > > A. Breathing more than 50% oxygen causes slow lung damage, and 100% starts to cause damage and edema in only 24 hours (at normal atmospheric pressure-- even faster at higher pressures). > > Q. Breathing pure oxygen at sea level (1 atmosphere) will result in fatal lung disease in about 48 hours. What is the mechanism? > > A. Some kind of oxidation injury to membranes in lung tissue. Probably standard free radical type stuff. You can measure increases in pentane and ethane production, and these are mediated by direct oxidation of membrane unsaturated fatty acids. It’s very much like what happens when oil-based paint “dries”. So, it looks like the “health problems” would be lung damage if you kept it up for more than a few hours. Under certain circumstances, spacewalkers breathe pure oxygen for longer periods of time than the typical “oxygen bar” hit, but bear in mind that the astronauts are all in excellent physical condition to begin with, and they’re being closely monitored while they do it. [http://spaceflight.nasa.gov/station/eva/outside.html](http://spaceflight.nasa.gov/station/eva/outside.html) > [@](#): > > Therefore, spacewalking crewmembers must perform a pre-breathe protocol, which is designed to wash out any excess nitrogen from the body, before a spacewalk. This protocol takes advantage of the fact that exercise increases the speed at which nitrogen is removed from the body by increasing blood circulation through the extremities. The ISS pre-breathe protocol involves breathing pure oxygen for a total of 2 hours and 20 minutes and includes a short period of high-intensity exercise at the beginning of the pre-breathe procedure. > > Station astronauts begin the pre-breathe protocol by exercising vigorously on the space station’s cycle ergometer for a total of 10 minutes while breathing pure oxygen via an oxygen mask. After 50 total minutes of breathing pure oxygen, including the 10 minutes initially spent exercising, the pressure in the station’s airlock will be lowered to 10.2 pounds per square inch, or psi. During airlock depressurization, the spacewalkers will breathe pure oxygen for an additional 30 minutes. At the end of those 30 minutes, with the airlock now at 10.2 psi, the spacewalkers will put on their space suits. Once their spacesuits are on, the spacewalkers will breathe pure oxygen inside the suits for an additional 60 minutes before making final preparations to leave the station and begin their spacewalk. This protocol provides a total of 2 hours and 20 minutes of pre-breathe time, including the 10 minutes of vigorous exercise at the beginning of the procedure. Hyperbaric oxygen therapy has you breathing pure oxygen for 20 to 90 minutes, but again, it’s under medical supervision. Also, I found this. [http://www.c-f-c.com/specgas\_products/oxygen.htm](http://www.c-f-c.com/specgas_products/oxygen.htm) > [@](#): > > There are four kinds of oxygen that are merchandised or sold to users; Aviation, Medical, Welding and Research…Also of interest, we have been told by the suppliers of welding oxygen, the purity level required for welding and cutting purposes is more critical than for breathing. [http://www.airproducts.com/maxx/cutting-oxyfueladvice.asp](http://www.airproducts.com/maxx/cutting-oxyfueladvice.asp) > [@](#): > > Oxygen purity > > The purity of the cutting oxygen can have a significant effect upon the cutting speed. > > The standard industrial grade oxygen is 99.5% pure. An increase in the oxygen purity will allow an improvement in the cutting speed, although the additional cost of the oxygen may make it uneconomic. Oxygen of a lower purity would reduce the cutting speed. So it’s possible that that tank of welding oxygen down at the hardware store may be even purer than you realize. And, um, anytime you’re dealing with pure oxygen, remember that it’s extremely flammable. Apollo 1, yes? **Disclaimer:** On behalf of the Straight Dope Message Board, Cecil Adams, the Chicago _Reader_, its heirs and assigns, I would like to remind you… DO NOT GO DOWN TO THE HARDWARE STORE AND BUY A TANK OF WELDING OXYGEN AND TRY HUFFING IT AT HOME!! End of disclaimer. 😃 ---
**Author:** ![Davebear](https://avatars.discourse-cdn.com/v4/letter/d/bcef8e/32.png) [@Davebear](https://boards.straightdope.com/u/Davebear)\ **Post date:** [March 8, 2003, 6:18pm UTC](https://boards.straightdope.com/t/industrial-breathing/159813/3 "2003-03-08T18:18:38Z")
> [@](#): > > \*Originally posted by Duck Duck Goose \* > **And, um, anytime you’re dealing with pure oxygen, remember that it’s extremely flammable. Apollo 1, yes?** Great post, except for this. Apparently, this isn’t true. I always thought so, too, for the same reason, but see this [Link](http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=166721&highlight=water+burn). Obviously, caution is still required, though. 🙂 ---
**Author:** ![drachillix](https://avatars.discourse-cdn.com/v4/letter/d/48db29/32.png) [@drachillix](https://boards.straightdope.com/u/drachillix)\ **Post date:** [March 8, 2003, 6:28pm UTC](https://boards.straightdope.com/t/industrial-breathing/159813/4 "2003-03-08T18:28:47Z")
> [@](#): > > So it’s possible that that tank of welding oxygen down at the hardware store may be even purer than you realize. No fault to **DDG** , welding oxygen is very chemically pure, but medical oxygen is IIRC supposed to be sterile. No such guarentees on welding gases. A little nitrogen in medical oxygen is no biggie, but bacteria or viral contamination would be ugly.