HUNTERSVILLE, N.C., Nov. 28, 2012 /PRNewswire/ -- Reusable Water Bottles that require hand washing have a higher environmental impact than those that are dishwasher safe, according to an independently third-party reviewed lifecycle assessment study (LCA) sponsored by Rubbermaid® and conducted by Environmental Resources Management. The household washing of reusable water bottles represents the largest component of a bottle's environmental impact because the energy needed for a residential water heater is much higher than the electricity consumption for a dishwasher when washing the same amount of place settings. As plastic and stainless steel bottles are recommended to be dishwasher safe, they were found to have significantly lower environmental impact across a wide range of categories when compared to aluminum bottles. "At Rubbermaid, our goal is to make products that fit consumers' lifestyles and we take into consideration how consumers will use our products," said Dave Zak, Director of Research & Development at Rubbermaid. "This study validated our strategy of making only dishwasher-safe bottles. In addition to being more convenient for consumers, they also create significantly less environmental impact in the long run." The LCA examined the four most widely-available water bottle materials in the U.S. and Canada --- aluminum, stainless steel and two forms of plastic (TRITANTM co-polyester and polypropylene, which are used by Rubbermaid and other plastic bottle makers). The study assessed the products from cradle to grave (from manufacturing to disposal) including the effects associated with the extraction of raw materials, bottle manufacturing and packaging, distribution to retail locations, use of the water bottle and disposal. Conclusions from the study stemmed from an assessment of 10 environmental impacts, including global warming, non-renewable energy, mineral extraction and carcinogens. One of the most critical differentiators between water bottle types, with regard to environmental impact, was the method of washing. Manufacturers of aluminum bottles recommend hand washing, and manufacturers of steel bottles recommend hand and dishwashing, while Rubbermaid recommends putting its plastic bottles, which are BPA-free, in the dishwasher. Due to the large number of times water bottles are washed over their lifetime, both types of plastic bottles were found to have significantly lower environmental impact across a wide range of categories when compared to aluminum bottles.