Safety in stories - a medium to convey hazards in confined spaces like tunnels

Last week, I  went to my home town and read a novel during the time. In the story, enemies plant a time bomb in a tunnel right under the building where a meeting with several important personalities is in progress. The main character working in the country's premier investigating agency suspects the location and tries to reach the spot through a tunnel. These lines are also punctured to release the gas. This tunnel also has gas lines and bomb explosion at a scheduled time will lead to a gas explosion with consequences for large scale destruction.

Anywhere, when a person has to enter a confined space like the tunnel described above, oxygen and other gas levels have to be checked first and take measures. As the issue in the story is of national importance, personnel enter inside, get exposed to the gas. Still, they go ahead and one of the person in the team, an expert in bomb disposal safely makes it inactive. Though the person gets unconscious, brought out by team members, finally survives and receives a medal.

The lesson for the readers is that, persons in tunnels can risk their lives due to gas or lack of oxygen. Though, initially I thought that the author should have considered safety aspects while continuing with the story, on brighter side, those who understand the dangers faced by the characters will atleast remember the same.

EHS Today - worker suffers burns due to fire from rich oxygen work atmosphere

http://www.ehstoday.com/construction/worker-severely-burned-when-trapped-fiery-underground-duct?NL=OH-05&Issue=OH-05_20171116_OH-05_712&sfvc4enews=42&cl=article_4&utm_rid=CPG03000007741031&utm_campaign=23112&utm_medium=email&elq2=4c69ad8c5a1d4c0f9872eb2a45dd0031

A worker suffered third degree burns due to a fire while working inside a duct that had rich oxygen.

The contractor was charged for safety lapses in confined space work, i.e. failure to ensure work area air monitoring, mechanical ventilation.

Many do not know the hazards of oxygen above atmospheric levels of 21% v/v. One should not think that compressed air and compressed oxygen are same.

Dress soaked in oxygen can catch fire easily. Materials burn easily in high oxygen conditions. 

Higher oxygen levels can cause damage to lungs and eyes.

That's the reason why safety professionals ask for measuring and finding reasons for oxygen levels in work area which are not at 21% v/v. 

Even if it is low, even slightly below 21% also, one should not think it is okay, because the difference can be some toxic/poisonous and pose health hazard. Similarly, for higher levels.

Then, we should ensure supply of fresh air (not oxygen) in the confined space work area. Generally, we supply air into the work area for 24 hours before work. Again, the work atmosphere will be measured for safe condition before permitting the persons inside.

Then buddy system also is to be ensured.

Worker dies of acid burns

In an incident, when four workers were cleaning an acid tank in a factory, acid and other chemicals fell on the persons and one died while others suffered burn injuries. It is not clear from the news report, how acid fell but clearly it is a work in confined space and one has to take all precautions for such jobs to avoid such incidents. The minimum precautions to be taken are,

1. List out safe procedure, job hazard analysis and ensure safety measures for identified hazards
2. Obtain safety work permit
3. Empty the contents from the tank by pumping / draining
4. Clean the tank by water circulation or with suitable medium and test for presence of acid by sampling the circulated water
5. Isolate all inlet lines positively by inserting a blind/slip plate and not by merely closing the valves as leaking of valves is possible
6. Display caution boards at the tank pump switches for not to operate and about the work in progress and if available, remove the fuses and keep in safe custody
7. Ensure LOTO
8. Open the vent lines and admit compressed air to ensure oxygen levels at the actual place of work same as that of atmospheric air
9. Use only 24 V supply for electrical fittings inside 
10. Provide proper access and illumination 
11. Ensure work area and escape routes are free from obstructions
12. Inform medical and fire teams about nature of work and location, before start of work
13. Ensure proper breathing air set suitable for use in case of emergency, or ensure BA set use during entire work
14. Follow buddy system by having one person outside to watch for every person inside
15. Ensure to engage only medically fit personnel for the job and brief the hazards, safety measures and emergency procedures to be followed
16. Carry out trial run before start of work
17. Ensure continuous competent supervision during entire period of work

http://www.thehindu.com/todays-paper/tp-national/article3902905.ece?textsize=small&test=2

SafetySmart Compliance » Blog Archive The James Beals Tragedy: The Price of Neglecting Confined Spaces Safety

SafetySmart Compliance » Blog Archive The James Beals Tragedy: The Price of Neglecting Confined Spaces Safety

The above link is about confined space tragedy in which a person died due to asphyxiation. Oxygen levels should be measured at the actual place of work before entry and every time before entry so that safe work atmosphere can be checked and ensured. Confined space hazard evaluation should be carried out however short the work is and do not believe by words but verify safe work atmosphere with measurements before entering the confined space.

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.
LINK

Two sewage workers die in a sump of 6 feet depth

A worker engaged in routine maintenance of a pump located six feet below in a sump inhaled poisonous hydrogen sulfide gas and collapsed. Another person who tried to rescue the exposed  was overcome, collapsed and died. Shift supervisor who tried to rescue the persons also lost his life. Four others who tried to rescue were also exposed to the poisonous gas.

This incident shows lack of use of self contained breathing apparatus by the workers involved in such jobs and supervision. Whether the work atmosphere is monitored for toxic gases and sufficient ventilation is provided is to be ascertained.  Even if the work is required to be done only for few minutes, people involved should use necessary safety gear, as many think it is a short job and thus don't need self contained breathing apparatus. Rescue procedures in such incidents also need to be planned before start of work so that there will not be any delay to save the lives. It should form part of procedure to inform fire service crew and doctors before taking up any such work that help can be rendered in shortest time possible during any eventuality. 

Though, these procedures are made and followed in industrial establishments, similar procedures should be made compulsory in departments where persons are likely to be exposed to hazardous environment, where person have to work in confined spaces and so on. If somebody has to work at a place which is not meant for regular use, it should be treated as confined space and safety procedures for confined space should be followed.

http://timesofindia.indiatimes.com/city/delhi/Toxic-gas-kills-2-Delhi-Jal-Board-men-safety-suspect/articleshow/14190479.cms

A video on confined space hazards

A video on confined space hazards from youtube.