Inspect the vent caps for proper functioning. Always wear acid-resistant gloves and long sleeves when cleaning batteries, avoiding any splashing of debris or acid into the face and eyes. Keep batteries away from children. Batteries are not toys. A child could be burnt or blinded while playing around a battery.
Charged batteries can give off heat and harmful gases.
Ventilation is necessary in the battery area. Vented batteries emit explosive gases when being charged. Ventilate the charging area. Never smoke or have open flames in a non-ventilated battery area. Explosive gases can be set off by a match, incorrect connection of battery cables, and careless use of tools around the battery.