Date: Tue, 28 Jan 2003 12:47:00
Those volume thresholds are taken from NFPA Code 30 for Flammable and Combustible Liquids. OSHA took them directly for their regs. In fact, a lot of 29 CFR 1910.106, Flammable and Combustible Liquids, is taken from NFPA Code 30.
But there are other NFPA Code 30 requirements not incorporated into the OSHA regs. So R.L. Holdcraft is correct in that you have to check both in order to comply with OSHA and satisfy applicable local ordinances that may incorporate by reference NFPA requirements.