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Nitrogen Safety in the Lab

This blog explains why nitrogen gas generators are the safest way to supply nitrogen to your instrumentation and why they pose no danger, in terms of changing atmospheric levels of nitrogen or oxygen.

The biggest danger to lab personnel is a rapid depletion of oxygen levels in the lab. Once the level of oxygen reduces to <18% there is a risk of impaired judgement and physical ability (Figure 1). For serious risk to the wellbeing of lab personnel, the O2 content of the lab would need to be reduced below 11%. To reduce the level of O2 in the atmosphere of a laboratory measuring 3m x 3m x 2.5m, which has a total volume of 22,500L, would require 675L of N2 to be released instantaneously to decrease O2 levels by 3%, and 2250L of N2 to reduce O2 levels below 11%.

Oxygen levels

A nitrogen gas generator producing 32LPM  of nitrogen would take over 20 minutes to produce 675L and over 1hr to produce 2250L of nitrogen. The 32LPM produced would at worst increase nitrogen levels by 0.14% per minute, assuming there was no air exchange within the room and this temporary separation of air has no effect on the overall air composition.

Nitrogen used by the instrument is vented back into the room, so there is no appreciable change in the overall levels of oxygen or nitrogen, the gases are only temporarily separated. Again, the amounts of gas that are temporarily separated by the generator are so small compared to the volume of air within the laboratory that the effect is negligible. In terms of nitrogen generator performance, if the oxygen content of the air in the room were to rise over time, the purity of N2 from the generator would gradually decline. The output from all of Peak’s nitrogen gas generators is consistent over time, demonstrating that the overall concentrations of N2 and O2 in the lab atmosphere are not changed by the gas generator.

View our full range of nitrogen gas generators    

If we contrast the amount of nitrogen that is contained in a cylinder of nitrogen (9000L) or the amount of gas that is produced from 1L of liquid nitrogen (700L), it quickly becomes apparent that a significant leak from a cylinder or spillage of liquid nitrogen poses a much larger risk to laboratory personnel, since this can cause an instantaneous change in levels of O2 in the lab atmosphere to below 11%, through loss of only 25% of a cylinder’s contents or a spillage of just 3L liquid N2.

For this reason, the NERC (Natural Environment Research Council UK) in their “Guidance on Design of Safe Laboratories” recommend a nitrogen or hydrogen gas generator. Click here for more information.

This document outlining the dangers of nitrogen from bulk supply, further illustrates the benefits of having an N2 generator in the lab from a health and safety aspect.

If you would like to know more about nitrogen safety or have any questions please contact us. You can also download and keep our Nitrogen Safety document which contains the information in this blog.

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Comments

Clara Lo - 13/01/2020 03:35
We are planning to install 2x 5040. The compressors will be in another room adjacant to the nitrogen generators room. The mass spectrometers will be in a room far away from the nitrogen generators room. The room size is around 12 m3. What is the air exchange rate in the room required so that there is no accumulation of oxygen inside the room?

Thanks!
Gabby Spiteri - 13/01/2020 11:24
Hi Clara,

Thanks for your enquiry.

That's not an issue to have the generators in another room - they can be installed as close or far away as you need.

Nitrogen used by the instrument is vented back into the room, so there is no change in the overall level of oxygen or nitrogen in the room - the gases are only temporarily separated. The volume of oxygen required to change the % level of O2 in a typical lab would be thousands of litres. An appreciable change in % level of oxygen, would require nitrogen to be supplied to a separate room, and for the generator to be in a hermetically sealed room, without any ventilation. What is more, our nitrogen generators produce N2 on demand and, unlike gas cylinders, do not store large volumes of gas, which can pose a safety hazard due to risk of asphyxiation in the event of a leak.

Regarding accumulation of O2 in the room, no laboratory - except where extremely hazardous substances are being quarantined - is a sealed environment, therefore the build-up of O2 is impossible. There are, however, regulatory standards and best practices in place for laboratory ventilation, that must be adhered to at time of installation, which all HVAC engineers will be familiar with. For reference, you can consult the recommended guidelines in the American Society of Heating, Refrigeration & Air Conditioning Engineers (ASHRAE) Handbook - available via https://www.ashrae.org.

Should you require further information or to submit a quote, please visit: www.peakscientific.com/contact/

Thank you

Kind regards,

Gabby
Gabby Spiteri - 13/01/2020 11:25
Hi Clara,

Thanks for your enquiry.

That's not an issue to have the generators in another room - they can be installed as close or far away as you need.

Nitrogen used by the instrument is vented back into the room, so there is no change in the overall level of oxygen or nitrogen in the room - the gases are only temporarily separated. The volume of oxygen required to change the % level of O2 in a typical lab would be thousands of litres. An appreciable change in % level of oxygen, would require nitrogen to be supplied to a separate room, and for the generator to be in a hermetically sealed room, without any ventilation. What is more, our nitrogen generators produce N2 on demand and, unlike gas cylinders, do not store large volumes of gas, which can pose a safety hazard due to risk of asphyxiation in the event of a leak.

Regarding accumulation of O2 in the room, no laboratory - except where extremely hazardous substances are being quarantined - is a sealed environment, therefore the build-up of O2 is impossible. There are, however, regulatory standards and best practices in place for laboratory ventilation, that must be adhered to at time of installation, which all HVAC engineers will be familiar with. For reference, you can consult the recommended guidelines in the American Society of Heating, Refrigeration & Air Conditioning Engineers (ASHRAE) Handbook - available via https://www.ashrae.org.

Should you require further information or to submit a quote, please visit: www.peakscientific.com/contact/

Thank you

Kind regards,

Gabby
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