Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Q&A

Post History

80%
+6 −0
Q&A Could a high-pressure, low oxygen atmosphere reduce fire risk while still being breathable?

Years ago I read a letter in a magazine suggesting a method for reducing the fire risk in an enclosed environment such as a space shuttle. The idea was to reduce the oxygen concentration to the po...

1 answer  ·  posted 2y ago by Pastychomper‭  ·  last activity 2y ago by dsr‭

#1: Initial revision by user avatar Pastychomper‭ · 2022-02-18T16:26:30Z (about 2 years ago)
Could a high-pressure, low oxygen atmosphere reduce fire risk while still being breathable?
Years ago I read a letter in a magazine suggesting a method for reducing the fire risk in an enclosed environment such as a space shuttle.  The idea was to reduce the oxygen concentration to the point where most common materials won't readily combust, and compensate by increasing the pressure so that the partial pressure of oxygen was the same as it is in "normal" air at sea level, making it breathable.  

The assertion was that the ppO<sub>2</sub> is the deciding factor in oxygen-haemoglobin binding, so a person could live comfortably in such an atmosphere, but the increased pressure would not increase the fire risk.

I understand deep-sea divers sometimes use reduced oxygen concentrations to compensate for high pressure, so the first part  seems reasonable.  However it seems to me that a higher ppO<sub>2</sub> would also make oxygen more readily available for other reactions, including fire, and at least some fires do burn faster at higher pressures. Hence I wouldn't expect much benefit, if any.  I have looked for research on the topic but drawn a blank, which might be a clue about the likely efficacy.

**Would using a high-pressure, low-oxygen atmosphere as described give any useful reduction in fire risk?**