§ 456. Location of magazines. The quantity of explosives that may be stored in any explosives factory or magazine shall depend upon its distances from the nearest building, railroad or highway or other magazine. The distances that a quantity of explosives may be stored from the nearest magazine, building, railroad or highway, shall be as determined by the regulations promulgated pursuant to this article. All such distances may be reduced one-half when the magazine, building, railroad or highway to be protected is adequately screened from the explosives factory or magazine by an efficient barricade as defined in subdivision seven of section four hundred fifty-one of this article.