Code of Practice for Fire Safety of Industrial Buildings - Saw Mills and Wood Works
2000 Edition

To mitigate fire hazards in saw mills according to the standard, it is advised to implement fixed fire extinguishing systems using inert gases within wood grinding mills, dust and pulverization extraction setups, and conveyor enclosures handling wood dust or chips. Employing fire-retardant or non-combustible materials for interior surfaces is recommended. Properly designed dust and chip extraction systems should be maintained to reduce combustible dust accumulation. Electrical systems must be installed following safety norms and open flames must be avoided near flammable materials. Additionally, sprinkler and hydrant systems should be installed in large facilities, coupled with diligent housekeeping and use of explosion-proof equipment in areas with pulverized wood or flammable substances.

Dust extraction systems must incorporate fixed inert gas fire extinguishing units inside wood grinding and pulverizing mills, as well as conveyor enclosures. All components, including hoods, ducts, and air cleaning devices, should be fabricated from non-combustible materials. Fans used in dust handling should have blades and housings made from non-sparking materials such as bronze. The system should be designed to minimize air resistance, ensuring efficient dust capture at the source. It is preferable to position exhaust fans downstream of dust separators to reduce dust exposure; where this is not feasible, fans must be non-sparking or suitably lined. This design approach reduces ignition potential and controls dust accumulation, significantly lowering fire and explosion risks.

Electrical safety in wood processing structures requires that all lighting fixtures, switches, cut-outs, and distribution panels be dust-tight to prevent ignition from wood dust deposits, as stipulated in the code. Regular cleaning of sawdust and wood shavings is mandatory to minimize combustible dust accumulation. Electrical wiring for lighting must be enclosed in screwed steel conduits, while power wiring should be protected either by screwed steel conduits or mineral insulated copper sheathed cables. These precautions reduce the chance of electrical sparks igniting combustible dust, ensuring safer operation within wood processing environments.

Firefighting requirements for saw mill facilities include installing hose reels, wet risers and downcomers (for buildings with more than one storey), yard hydrants, automatic sprinkler systems, manual electric fire alarms, and automatic detection alarms. Water storage capacity for underground tanks ranges from 25,000 liters for small plots up to requirements defined by IS 3844 for larger areas, with additional terrace tanks. Fire pump capacities vary depending on building size, typically including electric and diesel pumps providing between 1,620 to 4,500 liters per minute. Sprinkler protection allows tripling of permissible floor area for single-storey and doubling for multi-storey buildings. Fixed inert gas fire extinguishing systems are recommended for dust and chip extraction areas.

To reduce fire hazards in spray painting and varnishing activities, strict cleanliness must be maintained, especially when using nitrocellulose-based solutions due to their high flammability. Paint residues and scrapings should be collected weekly in metal containers, wetted, and removed promptly to avoid accumulation. Flammable liquids must not be used for cleaning brushes or scrapers. Only a one-day supply of paints, varnishes, and lacquers should be stored within the operation area. Maximum permissible floor areas depend on construction type, with stricter limits for non-fire-resistant structures. Firefighting installations such as hose reels, automatic sprinklers, fire alarms, and sufficient water supply must be provided according to building size and occupancy.