What to do if no further control possible to reduce the OHS risk?

S

samsung

We had an observation during the stage -1 assessment.

"Organization needs to have adequate management program in place to control / reduce the severity level of risk associated with the operation of autoclave."

Scenario - We have an autoclave used to test the expansion of cement under the severest conditions, i.e. at 21 kg/cm2 pressure. The autoclave is operated in a moderately high occupancy area. the operators are qualified & trained, all mechanical safe guards in place, pressure guage is calibrated at the prescribed interval and a documented operation control procedure is followed by the staff. In addition, an emergency preparedness program (documented) is also in place and a copy is displayed in the operational area.

Based on our criteria of risk assessment, the residual risk is still very high in view of continuous exposure of people and the area being moderately occupied while the equipment is in operation.

There's no past history of any explosion in the plant during last 15 years nor any incidence heard of taking place elsewhere.

What more we can do to further reduce the risk level.

Request to share your experiences and best practices adopted.

I will appreciate your valued responses.

Thanks
 

somashekar

Leader
Admin
"Organization needs to have adequate management program in place to control / reduce the severity level of risk associated with the operation of autoclave."

I think I understand the scenario explained, but the observation statement I read makes me think how ever can one control or reduce the severity level, since in the event of occurance of an incident after all possible reduction in its probability, whatever severity is associated with it sticks with it.
The next step perhaps is like creating an engineering control (considered under a management program) by having a concrete wall seperating the autoclave from the people nearby such that even in the event of an unlikely explosion, a barrier is created to reduce the impact to the persons nearby and now with the wall included, the residual risk due to an incident can be different and less. The operation control procedure can mention about persons and location during the autoclave operation.
 
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Jen Kirley

Quality and Auditing Expert
Leader
Admin
I have a question. What is at risk of exploding - cement dust from the autoclave's heat or spark? Is the autoclave gas fired?
 

ScottK

Not out of the crisis
Leader
Super Moderator
I have the same primary question as Jennifer...

And I agree with Somashekar in that the next control might be to isolate the machine in an enclosure of either concrete or steel with a high burn through rating.
 
S

samsung

I have a question. What is at risk of exploding - cement dust from the autoclave's heat or spark? Is the autoclave gas fired?


I have the same primary question as Jennifer...

And I agree with Somashekar in that the next control might be to isolate the machine in an enclosure of either concrete or steel with a high burn through rating.

Neither dust not spark. It's electrically fired. Cement specimen are heated at about 215 degree C in water for around 3 hours inside a stainless steel chamber of about 1" thickness. It's somewhat like a steam boiler. What makes the machine hazardous is the steam pressure (21 Kg/cm3) at which the machine is operated.

The equipment is housed in a room at the ground floor of a 3 storey building. There are many offices at the ground and upper floors whereas the top most floor houses all the electronics/ automation centres as well as the main control room from where the entire plant is operated.

With all available controls, it's unlikely (but not impossible) that it will go off yet, under the operating conditions, if the equipment explodes in the most unfortunate of the events, it can knock the entire building down in no time while claiming numerous casualties.

Thanks.
 

ScottK

Not out of the crisis
Leader
Super Moderator
Neither dust not spark. It's electrically fired. Cement specimen are heated at about 215 degree C in water for around 3 hours inside a stainless steel chamber of about 1" thickness. It's somewhat like a steam boiler. What makes the machine hazardous is the steam pressure (21 Kg/cm3) at which the machine is operated.

The equipment is housed in a room at the ground floor of a 3 storey building. There are many offices at the ground and upper floors whereas the top most floor houses all the electronics/ automation centres as well as the main control room from where the entire plant is operated.

With all available controls, it's unlikely (but not impossible) that it will go off yet, under the operating conditions, if the equipment explodes in the most unfortunate of the events, it can knock the entire building down in no time while claiming numerous casualties.

Thanks.

I can see why an insurance company might have issues :mg:

I'm not that familiar with cement manufacturing... what could cause and electrically fired oven to explode cement with that ferocity?

If it's that extreme I'd consider putting htis device in a separate room, detached from the building with red lights on every corner indicating when a test is in progress!
 
S

samsung

I can see why an insurance company might have issues :mg:

I'm not that familiar with cement manufacturing... what could cause and electrically fired oven to explode cement with that ferocity?

If it's that extreme I'd consider putting htis device in a separate room, detached from the building with red lights on every corner indicating when a test is in progress!

This autoclave is used in laboratory testing. Test conditions and operating procedure/ parameters have been prescribed by the regulatory authorities and are religiously followed.

Yes, one of the solutions can be the isolation of the hazard from the public place. I will discuss it with our people if it's workable.

Thanks.
 

Jen Kirley

Quality and Auditing Expert
Leader
Admin
A UCD Risk Assessment on autoclaves didn't include explosion due to failure of the unit itself, but from the business of loading, extracting and such use. Findings of safety evaluation at University of Oklahoma were similar, as was the risk evaluation at the University of Adelaide in Australia. Cardiff University's Guidance Document for autoclaves gives more information, but still focused on use and not explosion due to failure of the unit's physical integrity. Assemble enough of that kind of data and one can eventually decide risk of explosion is not severe enough to address, I expect with the exception of over-pressurizing the thing (if that's possible).
 
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somashekar

Leader
Admin
Neither dust not spark. It's electrically fired. Cement specimen are heated at about 215 degree C in water for around 3 hours inside a stainless steel chamber of about 1" thickness. It's somewhat like a steam boiler. What makes the machine hazardous is the steam pressure (21 Kg/cm3) at which the machine is operated.

The equipment is housed in a room at the ground floor of a 3 storey building. There are many offices at the ground and upper floors whereas the top most floor houses all the electronics/ automation centres as well as the main control room from where the entire plant is operated.

With all available controls, it's unlikely (but not impossible) that it will go off yet, under the operating conditions, if the equipment explodes in the most unfortunate of the events, it can knock the entire building down in no time while claiming numerous casualties.

Thanks.

The working pressure of 21 perhaps is far less than the safe working pressure of the autoclave, reading from the 1" thick steel housing and perhaps equally strong other mounted accessories.
Why not have a management program to install an emergency alarm which will activate when pressure inside the autoclave say reaches 25 or whatever safe limit feasible. This may be still far less than the pressure to explode the setup. This may activate when all other failsafe controls fails, and an evacuation to safe assembly area by all people will remove them from the site thereby the OHS purpose is acheived. The personnel who control at the third floor can also cut off all electrical supply to the autoclave as you say it is housed there, just before evacuating. Suitable drills of this situation can be put through and rehearsed.
Just my thoughts ~~~
 
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