Each 28 oz (800 ml) bottle uses BPA-free low density polyethylene, FDA approved for food products. Bottles are reusable and light weight. Seychelles 28 oz water bottle with filter. The patented ionic-adsorption micro-filtration system reduces almost all contaminants in the following groups - aesthetic contaminants - bad taste, odor, clarity, dirt, sediment and chlorine. Chemicals - chlorine, toxic chemicals, detergents, pesticides and other harmful industrial and agricultural pollutants. Dissolved solids - heavy metals such as aluminum, asbestos, copper, lead, mercury, chromium hexavalent and others. The Advanced filter is made of the same media as the standard Seychelles filter with the addition of EPA approved iodinated resin, which has been proven effective in the removal of bacteria and virus to six logs (99.9999%). Removes up to 90% of fluoride. It can be used in extreme conditions, turbid and stagnant water, and is ideal for emergencies such as hurricanes, cyclones, etc. such as events that occurred in the US with Katrina and the hurricane in Haiti. (Not to be used with salt water). Flip top 28 oz. Seychelles water bottle with filter replaces up to 757 half-liter water bottles. Stay green, get great tasting water and save the environment.