Any Experience with Oxygen-Reduction Systems?

1/23/2024

I had a client ask about Oxygen-Reduced Systems (ORS), aka Hypoxic air technology (displacing ambient oxygen in an enclosed environment such as in warehouses). I did a quick read with what's available on Wiki, FM and NFPA. But even my go-to suppression people have hardly encountered these. Testing has been very specific.

Just to increase my knowledge, does anyone here have an practical experience in these?

Are these systems really being installed?

Thanks in advance.

Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe

15 Comments

Sean

1/23/2024 08:08:39 am

I would recommend drawing in a vendor like Wagner (there may be others). They have started creating a presence here in the US and we are aware of several projects that have deployed ORS systems in warehouses.

WAGNER Fire Safety, Inc.
1670 Barclay Blvd,
Buffalo Grove,
Chicago, IL 60089
United States of America
Phone +1. 847. 243-4034
[email protected]

Glenn Berger

1/23/2024 08:12:03 am

My experience has been vendors telling me that these systems are being installed all over the place without proof.

Recommend avoiding these systems in all occupied spaces and any limited occupiable spaces.

Eddie

1/23/2024 08:26:15 am

How does one escape from the center of a warehouse if this system is activated?
NFPA has an article from 2018. The executive summary is interesting. Review of Oxygen Reduction Systems for Warehouse Storage Applications
By Patrick van Hees, and John Barton, Lund University; Martin Nilsson, Zurich Insurance plc; and Brian Meacham, Meacham Associates

Franck

1/23/2024 11:28:37 am

Eddie

The issue is not "when the system is activated" as this system is activated all the time !
The aim of this protection is to keep at all time the atmosphere of O2 below 16% to limit the possibility of a fire to occur.

I know, this seems crazy...

And it does not work for some fires such as the one generated by thermal runaway (lithium-ion batteries) or metal fire (to prevent/extinguish metal fires you need inerted atmosphere, generally of argon or helium).

Franck

1/23/2024 11:30:58 am

Fully agree.

I would even say... "Recommend avoiding these systems".

Greg

1/23/2024 08:50:56 am

I did review the oxygen reduced environment as a consideration within an AutoStore system. I'll put a link below as to what an AutoStore system is. My thought as to where an oxygen reduced environment could be considered was in a location that is not normally habitable. No one would normally be inside of the robotic type of storage systems. However, there a numerous safety tradeoffs that must be considered with a hypoxic technology system.

I felt that even though the reduced oxygen systems seem to advertise safety, the operational % O2 is on the fringe of impairment, and may have more debilitating effects on some than others. Reference NIH article, below.

As such, the addition of an engineered protective system for fire suppression considerations would require administrative controls and PPE ensure worker safety. It's somewhat of a difficult climb to balance both to a net positive, holistically. With any new technology, independent testing may improve hard data regarding these questions and be more emphatically positive around occupational safety. However, I didn't find conclusive evidence to this point and felt that these are early days for hypoxic technology to be introduce occupiable spaces, especially large spaces such as warehouses.

My recommendation as an alternative consideration would include (what I like to say as)...belt & suspenders thinking. If you're concerned about fire, be very very early in detection with air-sampling. Improve loss control with 2 hour fire wall separations that are above code minimum. Use fire wall enclosure with consideration for aerosolized systems as a supplemental fire suppression system tactic, and in addition to your sprinkler installation. Follow the guidance of FM Data Sheets for conservative sprinkler design and densities. If possible, change packaging to non-combustible or try to incorporate fire retardant packaging on the exterior of the product. Improve separation of stored products, or other segregation tactics.

My conclusion. It's very early days for hypoxic air technology and the capacity for systems to demonstrate remarkable fire suppression capabilities in all conditions. Not all occupational safety considerations appear to be fully investigated.

In the history of oxygen displacing fire suppression systems, the Idaho National Lab CO2 accident was the most influential in providing evidence that oxygen displacement must have engineering rigor to ensure physical lockout is available, and administrative controls to communicate the inherent hazard of oxygen deprivation. In the INL event, spurious equipment performance was a part of root cause, and these learnings should be considered as a real possibility within similar technologies where the breathable environment could be negatively impacted. Equipment can fail badly, and/or incorrectly provide false or misleading information that people believe to be true. Link to the INL event below.

AutoStore System Example
https://www.fortna.com/autostore/?_vsrefdom=ppcgoogle&msclkid=7e9d2db8e5171dbff9b3481728ae108b&utm_source=bing&utm_medium=cpc&utm_campaign=Autostore%20-%20GTP&utm_term=%2BAutostore%20%2BSystem&utm_content=Autostore%20Systems

Article, NIH Respiratory Protection for Oxygen Deficient Atmospheres
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7183576/

INL CO2 Accident Investigation
https://www.energy.gov/ehss/articles/type-accident-investigation-july-28-1998-fatality-and-multiple-injuries-resulting

Jesse

1/23/2024 09:05:02 am

Like Glenn, I've been told they're being installed "all over the place", but have yet to actually see any evidence of it.

Franck

1/23/2024 11:15:32 am

I yhave seen one of these systems in Sweden, in an electrical room (switchgear).
Theu have apparently been installed in Germany at some locations (including warehouses).
But the installations are hopefully very limited.
I don't like these systems for many reasons.

I will first speak about Health issues.

First, you have to consider the health effect of having a reduced level of oxygen.
Contractors say that this is similar as being in the mountains at very high altitude. This is not true. If the number of molecules of oxygen is reduced on a given volume at high altitude, the O2 concentration is still 20.9%...

OSHA (Occupational Safety & Health Administration) states in Paragraph (d)(2)(iii) of the Respiratory Protection Standard that any atmosphere with an oxygen level below 19.5 percent to be oxygen-deficient and immediately dangerous to life or health.
To ensure that employees have a reliable source of air with an oxygen content of at least 19.5 percent, paragraphs (d)(2)(i)(A) and (d)(2)(i)(B) of the Respiratory Protection Standard require employers working under oxygen-deficient conditions to provide their employees with a self-contained breathing apparatus or a combination full-face piece pressure-demand supplied-air respirator with auxiliary self-contained air supply.
In the preamble to the final Respiratory Protection Standard, OSHA discussed extensively its rationale for requiring that employees breathe air consisting of at least 19.5 percent oxygen.

People at greatest risk would be older employees and those with health conditions such as pulmonary disease, cardiovascular disease, or anemia.
Also, employees with lung disease and exertional demands greater than the resting level might experience greater hypoxemia.
In addition to potential adverse health effects, hypoxemia might also affect neuropsychiatric function, resulting in safety issues such as increased risk for injuries.

When I entered the room with low level of oxygen (it was around 16%), I had to sign a document saying that I have no lung or heart disease (do I really know) and that I have not smoke any cigarette over the last 24 h (would the people working in warehouse do that every day ?).

• At concentrations of 16 to 19.5 percent, workers engaged in any form of exertion can rapidly become symptomatic as their tissues fail to obtain the oxygen necessary to function properly. Increased breathing rates, accelerated heartbeat, and impaired thinking or coordination occur more quickly in an oxygen-deficient environment. Even a momentary loss of coordination may be devastating to a worker if it occurs while the worker is performing a potentially dangerous activity, such as climbing a ladder.
• Concentrations of 12 to 16 percent oxygen cause tachypnea (increased breathing rates), tachycardia (accelerated heartbeat), and impaired attention, thinking, and coordination, even in people who are resting.
• At oxygen levels of 10 to 14 percent, faulty judgment, intermittent respiration, and exhaustion can be expected even with minimal exertion.

Greg

1/24/2024 07:39:54 am

Franck provides very practical and first hand experience about concerns with oxygen deficiency and elevation (higher altitudes). The NIH article cited above in Greg's comment speaks to that in some depth and provides for a calculation - styled consideration. While the article was written from the perspective of wearing respirators, the physiological response to oxygen deprivation is the key - takeaway.

As Franck is describing, people can have different reactions based on physiological response. The NIH article describes people responding to oxygen deficiency (in the concentrations of ORS systems) to become euphoric and actually want to remain in that condition. Basically, it creates a feeling of being high and works against the normal response of evacuation.

Franck

1/23/2024 11:24:39 am

Now I will speak about the technical issues.

The main components of an oxygen reduction system are:
• Nitrogen generation system (to continuously generate nitrogen in order to keep the oxygen level under a certain %)
Note that automatic sprinkler protection should be provided for the gas generation room designed for the combustible load in the room.
• Electronic control device and alarms
• Oxygen sensors (within the room that is “protected” by the system, as well as in the gas generator room).
In the gas generator room, oxygen sensors should be provided and set to alarm if oxygen levels drop below 19.5% or increase above 23.5%.
These values are meant to define an environment that can be accessed by a person without any special considerations or equipment.

Nitrogen is produced as required and stored temporarily, if necessary.
This may involve central nitrogen supply facilities. The storage quantities may be either liquid or gaseous.

This means that you have a chemical plant to produce nitrogen close to your plant if the volume is not very limited.
Maintenance of such systems is not easy and any deficiency can lead to a too low level of oxygen that could be a threat to people working in such an environment.
Not to mention the cost on the long term operation (as you will be producing nitrogen all the time !).
Better to install a sprinkler protection system.

Note also that a fire can still occur, under some circumstances. • Reduced oxygen environment results in higher production rates of soot and smoke, which is also not a desirable thing...

I would normally suggest such systems only for limited volumes and areas where nobody is supposed to work inside. It would be more a "controled atmosphere" such as filled with nitrogen, than an oxyden reduction atmosphere.

FM Global data sheet 4.13 (Oxygen Reduction Systems) provides some guodance and should be strictly followed dor such installations.

But my best advice: chose an alternative protection system (sprinklers, total flooding gas protection system for a small volume...) !

Mark Harris

1/23/2024 01:17:22 pm

My understanding Wagner did a system in an automated warehouse in the Northwest a couple years ago. Probably have done more in the states since that. As I recall intent is forr automated storage not for normally occupied. Support areas (docks, offices, etc. would need different protection - sprinklers). The suppression design of taking oxygen below 15 percent would be similar to suppression with clean agent inert gas system. For inert clean agent systems NFPA 2001 states exposure should be limited to 5 minutes for up to 43% design - 12% oxygen and 3 minutes for up to 52% design - 10% oxygen.
Wagner did some presentations to SFPE Chapters a couple years ago. Can't remember what was said about redundancy or what if nitrogen supply had issues.

Anonymous

1/23/2024 06:12:58 pm

As the person who posted the question, I thank you all for your insightful and informative comments!

Pete

1/24/2024 06:14:16 am

My feeling is that there are a lot of technologies that will put the fire out. As an engineer/design pro, we kind of need to do our best to "do no harm " to people, except our mandate takes the form, "hold paramount the safety and welfare..." My mind jumps to the case studies of mishaps, and I try to consider them in the context that nobody set out to intentionally, say, level a school and kill 100 kids. When I have the need to think outside the box to protect some commodity, only as a last resort do I consider CO2 flooding, Halon 1301, high expansion foam, or any other method that could potentially kill someone in the process of protecting the property. Can it be safe? Sure. But, I would only consider after exhausting every other option, and not without a detailed risk analysis and system reliabilty calculation. I'd also consider ongoing maintenance cost and depreciation before choosing a hypoxic system.

James Art, FPE

1/24/2024 01:16:18 pm

The reduced O2 can be all the time.
Some whole warehouses for fruit or vegetable storage have reduced O2, to preserve the fruit longer.

They can have Sally Ports, 2 doors, and try to limit the number of times they enter. Fork lift drivers may use SCUBA gear.

But then they want to avoid sprinklers, the argument being fire is less likely!

Vijai Kumar

12/12/2024 03:19:05 am

This is a great topic being discussed here. I have been working at HBW for the past 8 years and we use the OXY reduct system supplied by Wagner. However, this system is not suitable for non-automated warehouses or enclosed spaces where staff are present inside, as it reduces oxygen levels up to 13-14%, compared to the normal level of around 21% inside the atmosphere. While the lower oxygen levels help prevent product damage from fire accident but same time maintaining the nitrogen level at approximately 85% incurs ongoing costs to the company. According to FM Global data sheet 4.13 (Oxygen Reduction Systems), there are protocol to work inside not more than 1.5 to 2 hours continuously and staff must be out side for 30 to 45 minutes in fresh atmosphere to re start his work again and this has been verified through specific medical tests (G28) for employees on regular basis.

Any Experience with Oxygen-Reduction Systems?

Leave a Reply.

ALL-ACCESS

SUBSCRIBE

COMMUNITY

YOUR POST

PE EXAM

FILTERS

ARCHIVES

PE PREP SERIES