Protect Yourself From Respiratory Hazards » SafetySmart

Good article from Safety Smart on the subject.
Protect Yourself From Respiratory Hazards » SafetySmart

Many times, persons actually doing the job also ignore the advice and try to do the job saying that it is a 2 minute job. And, they would never see the light again. Before carrying out any job, particularly in closed spaces, one should measure the concentration of all possible pollutants and also oxygen in the work atmosphere, particularly at the actual place of the work. Pollutants should be exhausted by proper ventilation so that oxygen levels are within permissible range. If it is suitable, one should enter the space by following all precautions. Else, they will become victims of dangerous work place. Though, people say 19.5% of oxygen is sufficient to enter a confined space, but still it is below 21% level in atmosphere. We should find out which are the pollutants in the work place that caused reduction in oxygen level to 19.5%. We know that carbon monoxide at 5000 ppm (0.5%) is fatal.
It is better to ensure oxygen levels nearer to atmospheric levels of 21%, else one should use self contained breathing apparatus (SCBA) so that one can work safely.
Apart from confined space jobs, respiratory protection is also required in jobs where fumes, mists, dust, etc are likely to be generated / present in the work place. Engineering measures should be taken and then as a last line of protection, one can go for personal protective equipment, in this case, use of respiratory protection.
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Asphyxiation - death of persons

Today, in a lecture, I heard about asphyxiation deaths, in which two persons died in a manufacturing facility. The reason was that instead of air, nitrogen gas was admitted in the work space in which they were working. This happened due to lack of colour coding on pipelines carrying air and nitrogen. Effect of different oxygen levels on human beings is listed below.

     
     % of O2     Effect
20 – 21            Normal
12 – 15            Muscular coordination for skilled movement is lost
10 – 14            Conscious, but judgment is faulty and muscular effort leads to fatigue
  6 – 8              Collapse occurs rapidly, but quick treatment prevents fatal outcome
       ≤ 6            Death occurs in 6 – 8 minutes
   > 60             Inhalation for several days may cause lung damage
35 – 40            Permanent visual impairment / blindness

·         A common symptom at low levels of exposure is headache. 

·         Depletion of O2 by combustion in a confined space may cause adverse health effects Some metals burn intensely in oxygen rich atmosphere (ex: iron wires)

·         Lubricating oil undergoes exothermic reaction causing intense burning in the presence of liquid oxygen

People question the need for measuring oxygen levels with the routine reply that they worked like that in the last 10 years.The main reason for the accidents is not the lack of the knowledge in our work place activities. It is the lack of application of the knowledge we already have.

An activity is being done in a particular fashion without any accident for a few years does not mean that it is safe. We have to remember the words of renowned safety professional, Trevor Kletz, “We have done this way a 100 times without an accident is not acceptable, unless, an accident on the 101^st occasion is acceptable to all of us”.