N.Y.C. Admin. Code § 27-409: § 27-409 Construction.

(a) Spray booths. Spray booths shall be substantially constructed of noncombustible materials. Panels of polished wired glass at least one-quarter inch thick, not exceeding seven hundred twenty square inches in area and not more than forty-eight inches in any linear dimension, may be used in the sides of spray booths.

(1) Spray booths shall be provided with a mechanical ventilating system meeting the requirements of section 27-410 of this article.

(2) Each spray booth having a frontal area larger than nine square feet shall have a noncombustible deflector or curtain at least six inches deep installed along the upper outer edge of the booth, over the opening, and shall be protected with an automatic sprinkler system. The interior of ducts shall be protected with sprinklers complying with the construction requirements of subchapter seventeen of this chapter, installed not more than twelve feet apart in horizontal ducts, and the sprinklers shall be accessible through duct access doors.

(b) Dip tanks. Dip tanks, including their supports and drainboards when provided, shall be of an approved type.