Q: "Having made provisions of bottled water in case of an emergency, I am wondering: how long can one keep bottled water after its 'best-by' date? Is it safe to drink it after that date? How long for? We have quite a few bottles, because the advice was three litres per day per person for at least three days."Sylvia
A: We asked Caroline Gunn, director of Food Safety Services Ltd in Napier, to respond:
"A shelf life for bottled water has not been established by anyone. The International Bottled Water Association (IBWA) advises consumers that bottled water can be stored indefinitely if out of direct sunlight, at room temperature (or cooler) and away from solvents and chemicals, eg. petrol, paint thinners and dry-cleaning chemicals. Grant Hall, CEO of Corporate Water Brands in New Zealand, says bottled water is fine to drink years after the 'use by' date; he said the only reason for the 'use by' date on their water bottles is for the benefit of the retailer for managing stock turnover or if there ever was an issue with the product.
If you're using your own containers to store water, firstly make sure they have been sterilised. Glass containers can be washed, rinsed and gently heated in the oven (80-100°C) for 5 minutes. Plastic bottles need to be cleaned; use boiling water to sterilise. Store as for bought bottled water: room temperature or below and away from sunlight and chemicals. If the container is clean and stored correctly, the water should not need to be changed but certainly do so if you start to detect off flavours or tainting.
Personally I've noticed everyday drinking water that I store in the fridge tastes better and lasts indefinitely when stored in glass bottles rather than plastic, so I prefer storing water in glass for long-term provision for emergencies.
On another note, in an emergency and if there is no bottled water available, you still may have the following options:
- Your hot water tank water.
- Boiling all drinking water.
- If you have no power, adding minute quantities of household chlorine bleach to drinking water: 1-2 drops per litre of water and let stand for 30 minutes. (NB: If water is cloudy, filter it first through a clean cloth as the chlorine won't work in murky water.)"