Annexure 2.6 EHS Guidelines
Rev.7, 2025
Guidelines For Kitchen Hoods Aand Exhaust Systems In Hotel And Factory Kitchen
Fires in kitchen are not uncommon with the most possible sources of fire being the cooking
equipment, hood and exhaust system.
The kitchen exhaust system typically consists of an exhaust hood over the cooking
equipment, grease filters, grease duct, duct enclosure and exhaust fan. Typical kitchen
exhaust system is shown in the following figure. Poor design, incorrect installation and poor
maintenance of any of these components and accumulation of grease inside and around the
ducts and hood can lead to fire. All Cooking equipment in kitchens in ITC units, shall be
equipped with properly designed exhaust system.
This document has been prepared to provide minimum guidance on installation and
maintenance of kitchen hood and exhaust systems, for kitchens in ITC units including hotels
and factories.
(For more details, please refer NFPA 96.)
Page 1 of 5
, Annexure 2.6 EHS Guidelines
Rev.7, 2025
2.6.1 Exhaust Hood:
a. The hoods shall be constructed of and be supported by steel sheet not less than 1.09
mm (0.043 in.) (No.18 MSG) in thickness, stainless steel sheet not less than 0.94 mm
(0.037 in.) (No. 20 MSG) in thickness, or other material of equivalent strength and
fire and corrosion resistance.
b. All seams, joints, and penetrations of the hood enclosure that capture grease-laden
vapors and exhaust gases shall have a liquid tight continuous external weld to the
hood’s lower outermost perimeter. Where seams, joints, and penetrations of the hood
are internally welded, such weld shall be made smooth, so as to not trap grease etc in
the joints, and is cleanable.
c. Internal hood joints, seams, filter support frames, and appurtenances attached inside
the hood shall be sealed or otherwise made grease tight.
2.6.2 Grease Filters in hoods
a. Exhaust hoods shall be provided with grease filters constructed of steel or equivalent
material and shall be of rigid construction that will not distort or crush under normal
operation, handling, and cleaning conditions.
b. Grease filters shall be arranged in such a way that all exhaust air shall pass through
the grease filters. Grease filters shall be easily accessible and removable for cleaning.
c. Grease filters shall be installed at an angle between 45-60 degrees from the horizontal.
2.6.3 Grease duct:
a. Grease ducts shall be constructed of and supported by carbon steel sheet not less than
1.37 mm (0.054 in.) (No. 16 MSG) in thickness or stainless steel not less than 1.09
mm (0.043 in.) (No. 18 MSG) in thickness.
b. All ducts shall be installed without forming dips or traps that might collect residues.
In manifold (common duct) systems, the lowest end of the main duct shall be
connected flush on the bottom with the branch duct.
c. All interior surfaces of the exhaust system shall be accessible for cleaning and
inspection purposes. Openings shall be provided in ducts and enclosures (shafts) for
inspection and duct cleaning etc.
d. Openings shall be provided at the sides or at the top of the duct, whichever is more
accessible, and at changes of direction.
e. Openings in ducts shall be protected with access panels constructed of the same
material and thickness as the duct. Access panels shall have a gasket or sealant that is
rated for 815.6°C (1500°F) and shall be grease tight.
f. A sign shall be placed on all access panels stating the following:
Page 2 of 5
Rev.7, 2025
Guidelines For Kitchen Hoods Aand Exhaust Systems In Hotel And Factory Kitchen
Fires in kitchen are not uncommon with the most possible sources of fire being the cooking
equipment, hood and exhaust system.
The kitchen exhaust system typically consists of an exhaust hood over the cooking
equipment, grease filters, grease duct, duct enclosure and exhaust fan. Typical kitchen
exhaust system is shown in the following figure. Poor design, incorrect installation and poor
maintenance of any of these components and accumulation of grease inside and around the
ducts and hood can lead to fire. All Cooking equipment in kitchens in ITC units, shall be
equipped with properly designed exhaust system.
This document has been prepared to provide minimum guidance on installation and
maintenance of kitchen hood and exhaust systems, for kitchens in ITC units including hotels
and factories.
(For more details, please refer NFPA 96.)
Page 1 of 5
, Annexure 2.6 EHS Guidelines
Rev.7, 2025
2.6.1 Exhaust Hood:
a. The hoods shall be constructed of and be supported by steel sheet not less than 1.09
mm (0.043 in.) (No.18 MSG) in thickness, stainless steel sheet not less than 0.94 mm
(0.037 in.) (No. 20 MSG) in thickness, or other material of equivalent strength and
fire and corrosion resistance.
b. All seams, joints, and penetrations of the hood enclosure that capture grease-laden
vapors and exhaust gases shall have a liquid tight continuous external weld to the
hood’s lower outermost perimeter. Where seams, joints, and penetrations of the hood
are internally welded, such weld shall be made smooth, so as to not trap grease etc in
the joints, and is cleanable.
c. Internal hood joints, seams, filter support frames, and appurtenances attached inside
the hood shall be sealed or otherwise made grease tight.
2.6.2 Grease Filters in hoods
a. Exhaust hoods shall be provided with grease filters constructed of steel or equivalent
material and shall be of rigid construction that will not distort or crush under normal
operation, handling, and cleaning conditions.
b. Grease filters shall be arranged in such a way that all exhaust air shall pass through
the grease filters. Grease filters shall be easily accessible and removable for cleaning.
c. Grease filters shall be installed at an angle between 45-60 degrees from the horizontal.
2.6.3 Grease duct:
a. Grease ducts shall be constructed of and supported by carbon steel sheet not less than
1.37 mm (0.054 in.) (No. 16 MSG) in thickness or stainless steel not less than 1.09
mm (0.043 in.) (No. 18 MSG) in thickness.
b. All ducts shall be installed without forming dips or traps that might collect residues.
In manifold (common duct) systems, the lowest end of the main duct shall be
connected flush on the bottom with the branch duct.
c. All interior surfaces of the exhaust system shall be accessible for cleaning and
inspection purposes. Openings shall be provided in ducts and enclosures (shafts) for
inspection and duct cleaning etc.
d. Openings shall be provided at the sides or at the top of the duct, whichever is more
accessible, and at changes of direction.
e. Openings in ducts shall be protected with access panels constructed of the same
material and thickness as the duct. Access panels shall have a gasket or sealant that is
rated for 815.6°C (1500°F) and shall be grease tight.
f. A sign shall be placed on all access panels stating the following:
Page 2 of 5
