Protection for ethilic alcohol 50% and its flash point.

[DavidCR]

We have a big storage tank for ethilic alcohol (700m3 tank, 10m diameter) and need to know what kind of fire protection is needed.

I started with the NFPA 30 and NFPA 11 aproach, and I want to know the flash point of the ethilic alcohol at 50% of concentration in order to clasify the substance.

Any other comment about the fire protection for such a tank will be valuable. Thanks in advance.