507.1 – 507.2
507.1.6 The listing evaluation of cooking equipment covered by section 507.1.5 shall demonstrate that the grease discharge at the exhaust duct of a test hood placed over the appliance shall not exceed 5 mg/m3 when operated with a total airflow of 0.236 cubic m e t e r s p e r s e c o n d ( 5 0 0 d m ) . [ N F P A 9 6 4 . 1 . 1 . 2 ] 5 0 7 . 1 . 7 T h e r e s p o n s i b i l i t y f o r i n s p e c t i o n , maintenance, and cleanliness of the ventilation control and fire protection of the commercial cooking operations shall be the ultimate responsibility of the owner of the system provided that this responsibility has not been transferred in written form to a management c o m p a n y o r o t h e r p a r t y . [ N F P A 9 6 4 . 1 . 5 ] 5 0 7 . 2 C l e a r a n c e . 5 0 7 . 2 . 1 E x c e p t w h e r e e n c l o s u r e s a r e r e q u i r e d , hoods, grease removal devices, exhaust fans, and ducts shall have a clearance of at least eighteen (18) inches (457.2 mm) to combustible material, three (3) inches (76.2 mm) to limited- combustible material, and 0 inches (0 mm) to noncombustible material.
Exception No. 1: Where the hood, duct, or grease removal device is listed for lesser clearances.
Exception No. 2: Reduced clearance to combustible material if the combustible material is protected as follows:
0.013 inch (0.33 mm) (no. 28 gauge) sheet metal spaced out one (1) inch (25.4 mm) on noncombustible spacers shall have nine
inch (228.6 mm) clearance to com-
(b) 0.027 inch (0.69 mm) (No. 22 gauge) sheet metal on one (1) inch (25.4 mm) mineral wool batts or ceramic fiber blanket reinforced with wire mesh or equivalent spaced out one (1) inch (25.4 mm) on non- combustible spacers shall have three (3) inch (76.2 mm) clearance to combustible material.
Exception No. 3: Reduced clearance to limited-combustible materials to zero clearance where protected by metal lath and plaster, ceramic tile, quarry tile, other noncombustible materials or assembly of noncombustible materials, or materials and products that are listed for the purpose of reducing clearance and are acceptable to the Authority Having Jurisdiction. The listed materials shall be installed in accordance with the conditions of the listing and the manufacturer's instructions and shall be acceptable to the Authority Having Jurisdiction.
2007 CALIFORNIA MECHANICAL CODE
507.2.1.1 Measures shall be taken to prevent physical damage to any material or product used for the purpose of reducing clearances. In the event of damage, the material or product shall be repaired and restored to meet its intended listing or clearance requirements and shall be acceptable to the Authority Having Jurisdiction. In the event of a fire within a kitchen exhaust system, the duct and its enclosure (rated shaft, factory- built grease duct enclosure, or field-applied grease duct enclosure) shall be inspected by qualified personnel to determine whether the duct and protection method are structurally sound, capable of maintaining their fire-protection function, and suitable f o r c o n t i n u e d o p e r a t i o n . 5 0 7 . 2 . 2 T h e p r o t e c t i o n m e t h o d s f o r d u c t s t o reduce clearance shall be applied to the combustible or limited-combustible construction, not to the duct itself.
Exception: Field-applied grease duct enclo- s u r e s a n d f a c t o r y - b u i l t g r e a s e d u c t e n c l o s u r e s . 5 0 7 . 2 . 3 F i e l d - A p p l i e d a n d F a c t o r y B u i l t G r e a s e D u c t E n c l o s u r e s . F i e l d - a p p l i e d g r e a s e duct enclosures and factory-built grease duct enclosures shall listed in accordance with UL 2221, Standard for Tests of Fire Resistive Grease Duct Enclosure Assemblies, or equivalent standard and installed in accordance with the manufacturer’s instructions and the listing r e q u i r e m e n t s . [ N F P A 9 6 : 4 . 3 . 1 ] 5 0 7 . 2 . 4 F i e l d - a p p l i e d g r e a s e d u c t e n c l o s u r e s and factory-built grease duct enclosures shall demonstrate that they provide sufficient mechanical and structural integrity, resiliency, and stability when subjected to expected building environmental conditions, duct movement under general operating conditions, and duct movement due to fire conditions. [ N F P A 9 6 : 4 . 3 . 2 ] 5 0 7 . 2 . 4 . 1 M e a s u r e s s h a l l b e t a k e n t o p r e v e n t physical damage to any material or product used for the purpose of reducing clearances.
Exception: When the duct is protected with a field-applied grease duct enclosure or f a c t o r y - b u i l t g r e a s e d u c t e n c l o s u r e . 5 0 7 . 2 . 4 . 2 T h e s p e c i f i c a t i o n s o f m a t e r i a l , gauge, and construction of the duct used in the testing and listing of field-applied grease duct enclosures and factory-built grease duct enclosures shall be included as minimum requirements in their listing and installation documentation. [NFPA 96: 4.3.3]