Once you open a tin can containing food like tomato paste, fruit or sardines, you may think it's fine to cover the opening with plastic wrap or aluminum foil and store it in the fridge. But once a tin can is open, it's not a safe food storage vehicle. Bacteria can grow along the edges of the can in no time at all, and highly acidic foods can take on a metallic taste. If you have leftover ingredients after opening a can, transfer the leftovers to an airtight container. Then be sure to toss the can in the recycling bin.

It can be nearly impossible to tell from just taste and smell if the water coming out of your tap is safe to drink. The good news is, if your home uses public or municipal water lines, your water provider can give test results for the water for free. Just look up the number on your water bill and call them up. Public water must be tested on a regular basis, and the company must offer customers something called a Consumer Confidence Report, which details the results of the testing. Many of these reports can also be found on the Environmental Protection Agency's website, epa.gov.

Lightly used yoga mats can be difficult to recycle. There are websites dedicated to interesting upcycling ideas, like cutting mats to make jar openers or a mouse pad for your computer, but the reality is that you can recycle your mat, and you should. On the website theboldermatcompany.com, the retailer has identified charities all over the United States that have a need for the mats. They're used for a whole host of purposes -- everything from extra padding for dog beds in shelters to free yoga and meditation classes for at-risk youth. And when buying a new yoga mat, look for ones made from recycled rubber or hemp.