Avoid Heat & Sunlight
With all containers (plastic, glass, metal, etc.) it is best to avoid heat and direct sunlight. This is especially important with plastic containers as leaching of toxins may occur. Also, if the water is acidic (below 7.0 pH) you will have a higher possibility of leaching toxins into the water.
It is recommended to sterilize your container every 8 to 10 uses. There are several ways to do this, and of course we recommend using a natural disinfectant/cleaner over anything with toxic chemicals. Regular white vinegar, natural bleach, baking soda, hydrogen peroxide and even lemon juice can do the trick. Be sure to rinse thoroughly after cleaning. If possible, allow the container to dry before using again and DO NOT seal or cap the container if there is any moisture inside. It's also smart not to seal or cap the container between uses.
Take the time to check the bottle for mold around the opening, or wherever water may collect for a long period of time. Some plastic containers are soft and porous or become more porous after many uses and should be discarded rather than risk your health.