National Fire Protection Association 1 - Separation
NFPA 1: 188.8.131.52.1 Separation Incompatible Materials
Separation shall be accomplished by one of the following methods:
(1) Segregating incompatible materials storage by a distance of not less than 20 ft (6.1 m)
(2) Isolating incompatible materials storage by a noncombustible partition extending not less than 18 in. (460 mm) above and to the sides of the stored materials
(3) Storing liquid materials in flammable liquids storage cabinets in accordance with 66.9.5 [30:184.108.40.206]
Please consult your local authority having jurisdiction with your questions and for guidance in conforming to laws as they apply to your application. This is only meant for a reference and does not imply a warranty.