Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

Helmut
Lv 7
Helmut asked in Science & MathematicsChemistry · 1 decade ago

What are the "outgassing" products when O2 is run through clear, flexible, vinyl tubing?

Since the manufacturer advertises the tubing as clear, flexible, vinyl tubing, I assume it to be plasticized PVC. When I change tubing it takes 48 to 96 hours to "passivate" the new tubing. During this time I experience severe headaches, irritated eyes, sinuses, and throat, and heightened anxiety and irritability. After about 4 days, this "newness" odor and the symptoms dissipate.

The only hard data I have on this process is that the O2 flowrate is 4 L/min. at 23 C and 1 atm, and that the tubing is 3/16 in. OD (probably 1/8 in. ID) and 30 ft long. (about 3 mm ID and 10 m long)

Is it possible with this scant data to estimate the quantity and type of gases being produced?

Update:

My condition is end stage COPD. That is a medical problem I have come to believe is congenital, exacerbated by silicosis, smoking, known HF, NH3, and possible Cl2 poisoning. I stopped smoking 5 years ago, but the improvement in lung function my doctors expected did not occur, yet other men and women with apparently less serious conditions have deteriorate rapidly and died. The only difference in treatment I have been able to discern is my adamant refusal to replace tubing frequently. I AM certain that 'outgassing' causes the additional symptoms described. These symptoms are similar to those of Cl2 or HCl poisoning

I can concoct many deadly gas formulae from PVC and O2, but I am not a chemist, and I need to know the most probable reactions occurring.

2 Answers

Relevance
  • 1 decade ago
    Favorite Answer

    Am I correct in assuming that you have emphysema and use this tubing as part of your pulmonary system? If so, this is a medical problem, and I wd not screw around with answers you get here from people with GOK what expertise (or lack thereof). I am an expert polymer chemist but wd not presume to advise you in this possibly serious matter. After all, you cannot be certain that 'outgassing' is the problem.

    I wd suggest that you consult:

    1. Your doctor, who shd be able to point you in the right direction after you describe your symptoms.

    2. The manufacturer of your equipment, who has very likely been exposed to this problem before.

    3. There are many types of flexible tubing available, not all plastcized PVC, and not all vinyls are plasticized. For general info you might start with http://en.wikipedia.org./ Plug Vinyl tubing in the search box for a start, then Tygon Tubing, then go on from there.

    4. The Saint-Gobain (manufacturer of Tygon) website offers much info on their products...and a phone call to them could easily solve your problem.

    Bottom line: When you have a medical problem, start by consulting your DOCTOR.

    Added later:

    Sorry, I had no intention of belittling you...but some young/bewildered/unknowleged people use this site. Glad to see that you keep your doctor informed.

    The relatively mild conditions you state are not likely to affect greatly either of the main components of plasticized vinyl: PVC and the plasticizer (if it IS plasticized).

    But PVC CAN be oxydized, replacing some Cl on the polymer with O, liberating HCl and other Cl compounds...in very small amounts. Also the PVC might contain traces of unreacted vinyl chloride, a v irritating gas.

    And the plasticizer MIGHT be oxydized...eg the earliest and cheapest one is dibutyl phthalate, which might revert in small part to butyl alcohol and phthalic acid. Also DBP is in itself v sl volatile, and may contain traces of unreacted BA and PA. But if your manufacturer knows the purpose of the tubing it is unlikely that this system was used...much safer alternatives are available.

    All-in-all much more info is needed in order to make any educated guess. I wd suggest, if you want to pursue this, that you follow 3. and 4. above. If you plug Plasticizer into wiki's search box you can gain some idea of the complexity involved here. Feel free to provide more info (email me), and I shall see if I can help you in your study of this problem.

    And Still Later:

    If you can afford/wish to you can have the system analyzed. Contact an analytical lab which can perform Vapor Phase Chromatography. They can run O2 through your (unused) tubing and gve you a detailed analysis of the gasses coming off...composition and amounts.

  • ?
    Lv 4
    4 years ago

    Vinyl Outgassing

Still have questions? Get your answers by asking now.