30 CFR § 56.6309
Fuel oil requirements for ANFO.
(a) Liquid hydrocarbon fuels with flash points lower than that of No. 2 diesel
oil (125°F) shall not be used to prepare ammonium nitrate-fuel oil, except
that diesel fuels with flash points no lower than 100°F may be used at ambient
air temperatures below 45°F.
(b) Waste oil, including crankcase oil, shall not be used to prepare ammonium
[58 FR 69596, Dec. 30, 1993]