Lead the Charge

Power to the Peeples is an exclusive Earth911 series written by Bob Peeples, our resident chemical engineer and Program Manager of Earth911’s sister site Beaches911. Bob combines his extensive knowledge of the environment and how things work with an off-the-cuff sense of humor.

About 25 years ago, we were looking at ways to reduce the mercury getting into the environment. Batteries were responsible for 56 percent of the mercury consumed by the U.S. The battery manufacturers went to work.

Creating a Charge

Lowering mercury levels in batteries was no easy process, because it (as well as lead) was used to fight galvanic corrosion. It helps keep the other metals within the battery in line. Otherwise, the battery tends to eat itself.

This mercury comes in handy for other uses beyond batteries, such as “silver” dental fillings. Our country’s crematories release an estimated 19,000 pounds of mercury per year by burning remains with dental amalgams. I’m also probably not the only child who was treated with Mercurochrome for my “boo-boos,” which is 25 percent mercury.

But mercury is one of only a few metals found in liquid form at normal temperatures, and it can leach out of dental fillings or batteries and cause serious health issues. The effect of mercury on human nerve tissue has been demonstrated in laboratory observations, so the fear that high mercury levels in batteries could hurt the environment was well-founded.

Establishing Polarity

In the early 90s, we assessed the progress of battery manufacturers’ efforts. Although mercury use in batteries had been dramatically reduced, it just wasn’t enough:

• The contribution from municipal solid waste was still six times greater than the next biggest source (coal fired plants)
• Batteries still contributed 35 percent of the total mercury to municipal solid waste

The Massachusetts Department of Environmental Protection claimed in a 1996 report that foreign imports were responsible for 82 to 94 percent of the mercury in our battery waste stream, since these manufacturers “may not have reduced the mercury content of their batteries to the same degree as U.S. firms.”

Battery manufacturers were forced to come up with a solution, or be regulated as hazardous or universal waste; this was one of the first product stewardship initiatives in the U.S. The solution was twofold:

1. To continue reducing mercury levels in alkaline and heavy duty batteries
2. To develop collection and recycling programs for batteries that have sufficient intrinsic value to make recycling cost-effective

So what does this mean for those who want to recycle single-use batteries, where the mercury levels are low or non-existent? Let’s put it this way: I still wince when municipalities encourage residents to “throw alkaline and heavy duty cells out with the regular trash.”

Charging Forward

We’ve come a long way from D-cell batteries with 10 grams of mercury (if a compact fluorescent bulb with four milligrams of mercury can contaminate 7,000 gallons of water, then 10 grams of mercury would contaminate 17.5 million gallons), but single-use batteries are by no means harmless to the environment. Consider:

1. We buy an awful lot of toys and electronic devices with batteries included—they aren’t usually made here where mercury content is regulated.
2. The regulation never really touched on battery lead content, and lead is also a major environmental (and health) concern.
3. At best, non-rechargeable batteries are non-hazardous by regulation only. Because the electrolyte material is contained within the cell in a “dry” form, pH of the water that it is dissolved in is indeterminable. This legal technicality doesn’t have anything to do with other measures of hazards, like aquatic toxicity.

There is no simple solution. If your household waste is headed for incineration, energy recovery or the backyard burn barrel, separate the batteries out and at least take them to the landfill with the ashes - if you cannot find a responsible recycler for them in your area. Batteries contribute 12 times the mercury to the environment through combustion over landfill sources, so the landfill is the best choice.