Avoid using Plastic Type 3 or 7

I've gotten the table below from Wikipedia. It basically describes the different types of plastics and according to what I have read, type 3 or type 7 plastics may contain Bisphenol A which is cancerous.

Morale of the story? Don't use plastic bottles for long periods of time. Get a water bottle.

Look at the bottom of the plastic bottle and you'll be able to see the indicator of the type of plastic being used. Refer to the table below on the different types of plastics.

Plastic Identification Code	Type of plastic polymer	Properties	Common Packaging Applications
	PET, PETE	Clarity, strength, toughness, barrier to gas and moisture.	Soft drink, water and salad dressing bottles; peanut butter and jam jars
	HDPE	Stiffness, strength, toughness, resistance to moisture, permeability to gas.	Water pipes, Hula-Hoop (children's game) rings, Milk, juice and water bottles; the occasional shampoo / toiletry bottle
	PVC	Versatility, clarity, ease of blending, strength, toughness.	Juice bottles; cling films; PVC piping May be cancerous as it uses Bisphenol A during polymerization or package forming
	LDPE	Ease of processing, strength, toughness, flexibility, ease of sealing, barrier to moisture.	Frozen food bags; squeezable bottles, e.g. honey, mustard; cling films; flexible container lids.
	PP	Strength, toughness, resistance to heat, chemicals, grease and oil, versatile, barrier to moisture.	Reusable microwaveable ware; kitchenware; yogurt containers; margarine tubs; microwaveable disposable take-away containers; disposable cups; plates.
	PS	Versatility, clarity, easily formed	Egg cartons; packing peanuts; disposable cups, plates, trays and cutlery; disposable take-away containers;
	Other (often polycarbonate or ABS)	Dependent on polymers or combination of polymers	Beverage bottles; baby milk bottles; electronic casing. May be cancerous as it uses Bisphenol A during polymerization or package forming