Death by Nitrogen

1
Death by Nitrogen

• Every year people die in nitrogen rich/oxygen
  deficient atmospheres because of ignorance,
  attitude and failure to adhere to safe work
  practices.

2
Nitrogen (N2) vs. Oxygen (O2)

• Nitrogen is not toxic it exists in air at 78.
• Oxygen in the air is typically 20.8
• When nitrogen concentration increases, oxygen
  concentration decreases.
• Note any compressed gas can also decrease O2
  concentration in an enclosed space by replacing
  O2.

3
Facts Figures -Liquid nitrogen

• One litre liquid gives 700 litres of gas
• Cold nitrogen is heavier than air so accumulates
  at ground level.
• When liquid N2 is exposed to air the cloudy
  vapour that you see is condensed moisture, not N2
  gas. N2 gas is invisible and this is the
  Danger!!!.
• OHSA recommend at least 6 changes of air per hour
  when using liquid N2.
• Other nitrogen risks pressure, frost, confuse
  LEL detectors.

4
Medical definitions

• Osmosis If you have a concentrated mixture on
  one side of a permeable membrane and a dilute
  mixture on the other, the flow of material will
  be from concentrated to the dilute side.
• Hypoxia reduction of O2 supply to the tissues
• Anoxia lack of O2 supply to the tissues.

5
Transport of oxygen
6
Oxygen Osmosis
Oxygen is transported from the lungs to cells,
tissue and brain via Osmosis.
7
What happens when you breathe in nitrogen?

• Reverse Osmosis
• Lungs take O2 from the blood stream which in turn
  takes it from the brain.

8
What happens when you breathe in nitrogen?

• Brain becomes starved of oxygen you pass out.
• You could say your brain shuts you down
• It only takes one breath!

9
Physiological effects
10
How long does it take to have an effect?

• When a person enters an oxygen deprived
  atmosphere the oxygen level in the arterial blood
  drops to a low level within 5-7 seconds.
• Loss of consciousness follows in 10-12 seconds.
• Heart failure and death ensue if person does not
  receive any oxygen in 2-4 minutes.

11
What If I hold my breath?

• Holding your breath causes the oxygen in your
  blood to be used up. If you then inhale the
  inert atmosphere, suffocation and death will
  follow in most cases (INRS ED 632)

12
Do I have to be in an enclosed space to be at
risk?

• No. Any situation where you can breathe oxygen
  deficient air has the same effect.
• Incident at Texas City where individual was
  working on top of reactor. He leaned over, got a
  blast of pure N2 and pitched forward into the
  vessel unconscious.
• Cold nitrogen is more dense than air so lower
  concentration at floor level. If you lean down
  into a liquid nitrogen spillage you are also at
  risk.

13
The last word.
Nitrogen is a silent killer and demands
RESPECT..!!! PLEASE CONTROL IT AND WORK
AROUND IT PROPERLY
14
What if I see a colleague who is unconscious?

• Call emergency services. - First as with all
  incidents
• Do not enter the area without self contained
  breathing apparatus.
• Over 50 of workers who die in confined spaces
  are attempting to rescue other workers.