Construction sites must have fire prevention plans identifying fire hazards and control measures. Fire extinguishers must be readily available and personnel trained on their use. Hot work including welding, cutting, and grinding requires precautions preventing ignition. Hot work permits issued by a responsible person document that precautions have been taken. Precautions include removal of flammable materials, covering of combustible items, and stationing of a fire watch. Fire watch personnel monitor the area for fires during and after hot work. Fires can develop hours after hot work due to heat penetrating into concealed spaces. Watch period of at least 30 minutes after work completion is typical. Safe areas for hot work must not have flammable liquids, gases, or materials within 35 feet (or per permit requirements). Temporary walls or barriers prevent ignition of materials outside the immediate work area. Liquefied petroleum gas (LPG) and acetylene cylinders used for welding must be positioned upright and secured. Storage must be separated from oxygen cylinders by 20 feet or a suitable barrier. Oxygen accelerates combustion and cannot be stored with fuel gases. Smoking is prohibited in areas with flammable materials. Smoking materials must be disposed of in designated receptacles. Electrical equipment must not create sparks or heat that could ignite flammable vapors. Proper grounding of equipment prevents static electricity accumulation. Communication of fire hazards to all personnel is essential; training on fire hazard recognition and emergency response ensures everyone understands their responsibilities.