Zoning for Methanol
Zoning for Methanol
(OP)
I'm an electrical engineer and have been asked a question because I've had some involvement with explosive atmospheres (ie vapours and dusts possibly igniting because of a spark or other heat source). Somone is importing and storing about 12 by 5 litre (About 60 Litre total or about 16 US Gallons) plastic containers of methanol in a warehouse. Should warehouse be zoned as a potntially explosive atmosphere (probably Zone 2 in European terminology) I'd be interested in anyones thoughts.





RE: Zoning for Methanol
RE: Zoning for Methanol
RE: Zoning for Methanol
I am going to give you basic information for methanol and you can decide what to do about methanol.
Methanol is extremely flammable and toxic. The flash point is 60.1 F (closed cup). The NFPA class is 1B flammable liquid. Explosive limits are 6% v/v in air (lower) and 36% v/v in air (upper). An ignitable or explosive mixture in air exists over methanol at temperatures of 60 F to 106 F. One needs to consider that an ignitable mixture in air exists in a small region over a spill. A large volume such as a warehouse will have several air exchanges and the methanol will disperse into non-ignitable mixtures.
The fire triangle requires the coincidence of fuel -- oxygen -- heat for ignition or explosion. Storage safety is based upon mitigating the potential for ignition sources.
More detailed information about good storage practices can be found at http://www.methanol.org. There is a good video and safety handbook for methanol usage. The Methanex corporate website has valuable information as well.
RE: Zoning for Methanol
Our insurance require special rooms for such storage of any quantity of flammable liquids in any quantity than that deemed for everyday use,
RE: Zoning for Methanol
Your three considerations should be:
1. the bottles are tightly closed
2. kept at room temperature - kept away from heated equipment, etc.
3. the room is relatively well ventilated
there should be no worries - it's flammable, but not so dangerous if these basic safety measures are taken into consideration
RE: Zoning for Methanol
Storage safety isn't just about mitigating ignition sources. That's the focus of the electrical codes because ignition is the only part of the triangle they have anything to do with.
If this is a filling or dispensing operation, that's a very different story!
If this is simply storage, a flame-resistant cabinet bonded and vented in accordance with the manufacturers' instructions will provide sufficient protection in most jurisdictions. That also presumes typical low-firespread construction (i.e. this is not an old wooden buildng), and the normal protections against fire are also in place (sprinklers, smoke/fire detection and alarming etc.). Div 2 electrical area classification for these circumstances would be equivalent to swatting a fly with a sledgehammer.
RE: Zoning for Methanol
Warehouses have thier own classification system for storing combustable and flammable liquids.
NFPA and the insurance companies know all about this.
It's all a question of quantity and fire protection systems.
I think that you want OSHA rules: "Flammable and combustible liquids. - 1910.106 "
http:
Just my opinion....
-MJC
RE: Zoning for Methanol