Industrial Safety - Storage of Flammable Materials & Sprinkler/Electrical fires

[Dr. L. Ramakrishnan]

Two situations that I often come across have been bothering me for quite some time. I thought I will share them with you here in the Elsmar Cove Forum and seek your views.

1. Often I come across storage of highly inflammable solvents (Flash Point less than 23 Deg C; quantities in the range of about 1000 to 2000 litres) in a special inflammable materials store room (flame proof electrical fittings, bunding etc.) at the ground floor of a multistorey building. I find this often in units which are not chemical units. To me this is a potential dangerous situation; if there is a fire, that may lead to the explosion of the solvent and collapse of the building. Am I right in my thinking ?

2. Often I come across fire detection and sprinkler systems used all over the building, irrespective of the potential cause of fire. If the potential cause of fire is "electric" is this a desirbale situation ? What is the probability of someone getting electricuted because of the sprinkler water flowing down ? We know that electricity should be put off in case of a fire; but what happens if the area where the main switch is located is already flooded with sprinkler water ?

I would appreciate your views. If there is a legal requirement covering these two issues, please share that too.

Thanks and with kind regards,

Ramakrishnan

[Ajit Basrur]

Hi Ramakrishnan,

I have moved your post to this appropriate section for getting directed responses.

[harry]

My 2 cents and from experience over here.

1. Our building bylaws would not allow this to happen (the type of storage you described would put them in the heavy industry category and they need to be in their own and seperate building and in certain zones only). Even the skid-tanks for storing diesel for the stand-by generator have to be away from the building proper or compartmentalized (fire-proof). Having said that, there are instances of overlook/conveniently overlooked and your fears are not unfounded.

2. I supposed statistically, incidence of electrical fire is much, much lower that the authorities mandate sprinkler systems all over. Exceptions being in electrical substations or control rooms. On top of that circuit breakers, sensors and others may have help a lot in these instances but the probability is stil there and a risk factor.

3. I have a phobia for piped-in gas. They are the main cause of explosions that I had read. I think legislations, enforcement and practices can only improve over time and they appear laxed in the developing countries.

[MIREGMGR]

In most locales of the US, the regulation of these and similar issues is based on NFPA (National Fire Protection Association, Boston, MA) model codes, not OHSAS 18001. The National Electrical Code is an example of the NFPA's work product.

NFPA flammables storage codes do not permit storage of such large quantities of highly flammable liquids within general-occupancy buildings, or within any (non-single-residence, non-farm) building except by design and permit. Code requirements governing the presence of flammable liquids within buildings are many and complex.

NFPA sprinkler, fire and building codes definitely encourage, and in many contexts mandate, provision of sprinkler systems throughout public-occupancy and industrial buildings, irrespective of the presence of electrical distribution system elements. The general thinking is that the local thermal conditions that cause wet-system head release are borderline non-survivable and certainly are unlikely to exist in the presence of occupants who are mobile and able to move toward safety; and, the potential for risk of harm from establishment of water-based conductivity is mitigated by the likelihood of simultaneous short-circuiting and system grounding resulting in upstream overcurrent-protective-device operation.

In the US, my understanding is that the operation of water sprinkler systems is considered to be a creator of safer conditions (flame knockdown, cooling, washout of breathing zone toxins/corrosives, prevention of flashover), not a contributor to hazardous conditions, within fire zones by professional fire personnel who conduct fire entry operations.