Lead batteries have the highest recycling rate of any product with estimates that 97 percent of the lead in batteries is processed for reuse, according to Battery Council International.

In most cases, recycling has unquestioned environmental benefits, but lead batteries that are recycled abroad can be significant contributors to environmental lead contamination. Although the recycling industry in the U.S. has made significant strides in recent years to improve efficiency and reduce lead emissions, a larger proportion of used batteries are now being exported for recycling in Mexico and other developing countries (see table 1).

Similarly, the manufacture of new lead batteries is highly regulated in the U.S., but plants operating in China and other countries have been the source of childhood lead poisoning in surrounding communities. There are, however, some simple precautions that data center operators can take to ensure that their company practices to avoid irresponsible manufacturing and recycling practices and the resulting negative consequences.


Lead batteries were invented in 1850s, and the underlying technology has changed little since that time. Although a number of alternative types of rechargeable batteries have been developed, lead batteries remain the most reliable and cost-effective batteries for stationary applications and are the most widely used for back-up power in data centers. Recent advances in new lead battery technology offer the potential to increase their lifespan and performance, but even without these improvements, the lead battery is expected to be the most competitive for these uses for decades to come. According to a 2011 Frost and Sullivan report, there is no threat of an industry transition to any alternative energy storage technology in the near term.

In 2010, the market for stationary lead acid batteries had revenues of $4.18 billion in 2010, which represents approximately 15 to 20 percent of all lead battery sales, according to Mike Weighall’s 2008 study, “Best Global Battery Report.” The global market for lead batteries to supply the telecommunications sector and data centers is expected to grow at a compound annual growth rate of 6.8 percent from 2011 to 2017 and reach $6.2 billion in revenue, according to Frost and Sullivan. And the Asia Battery Association reported that reserve power batteries account for approximately 28 percent of the lead battery market in China, which is the world’s largest producer of lead batteries.

Although electronic waste from computers and other electronics have generated considerable attention in recent years, used lead batteries may be a far bigger problem that has gone under the radar of most corporate social responsibility efforts. In fact, OK International found that the U.S. exports far more lead in used batteries than in all of the e-waste being shipped overseas. In addition, outside of the U.S. and E.U., few efforts have been made to address the environmental practices of lead battery suppliers to the data center industry, although there have been numerous mass lead poisoning cases reported in communities around these facilities.


Lead batteries are one of the most recycled commodities but even in developing countries, few of them end up in landfills or in waste dumps. In theory, the life cycle of the lead battery can approximate a closed loop, but there are significant environmental emissions in each step of the life cycle (see figure 1). When lead is melted down in the manufacturing and recycling process it becomes airborne and is released into the environment. Airborne lead emissions can be inhaled or settle on soil and dust, which are both significant sources of exposure for children. Water emissions are also a concern, as large quantities of water are involved in charging new lead batteries and in the processing of the acid from used lead batteries.

The lifecycle of any lead battery begins with mining and smelting primary lead ore or smelting of secondary (recycled) lead. The lead from both sources is sold to battery manufacturers who use it to produce new batteries.

Used lead batteries that are returned from data centers to manufacturers, distributors, or other collection centers are then shipped to recycling facilities. In the U.S. lead batteries are generally disassembled in a wet process to facilitate the treatment of the waste acid and to separate out the plastic components for recycling. The remaining lead is recovered through the smelting process and is sold to battery manufacturers to make new batteries (see figure 2).

Primary lead from processing ore can also release significant quantities of sulfur along with lead emissions and requires considerable more energy than recycling. In addition, mine tailings also include considerable lead contamination. Recycling is generally preferable if the plant is equipped with sufficient air and water pollution control technology.


The International Lead and Zinc Study Group reported in 2011 that the lead battery industry consumes more than 80 percent of the lead produced globally. Health and environmental concerns arise during the manufacture and recycling of these batteries but are not a problem while in use. This industry is highly regulated in the U.S. where new environmental regulations governing emissions have recently been introduced. Although occupational health regulations governing lead exposure in manufacturing and recycling are over 30 years old and are considered insufficient to protect workers, new efforts underway in California will update this standard.

Regulation and enforcement of existing requirements for this industry in developing countries are lagging behind those in the U.S and E.U. This is becoming more apparent as the industry is experiencing double digit growth in China, India, and other emerging market countries. Children living near plants that manufacture or recycle lead batteries in developing countries have blood lead levels that are 13 times higher than the average levels of children in the U.S., according to a 2011 paper published by the Journal of Occupational and Environmental Hygiene. Workers in these plants also have substantially higher lead exposures than their counterparts in the U.S.

Lead is one of the most toxic heavy metals and its adverse health effects were observed as long ago as the 2nd century BC. While severe lead poisoning can cause coma or death, most overexposed individuals have no obvious symptoms. Even moderate lead exposures to children impacts intelligence, school performance, and is linked to hyperactive and violent behavior. Lead affects the brain, kidneys, blood, and the reproductive system in both men and women. At relatively low levels, lead is also known to contribute to high blood pressure in adults.

China leads the world in lead production with 4.2 million metric tons produced in 2010, according to the China Battery Industry Association. The United Nations Comtrade online database lists that nation as the world leader in lead battery production due to strong internal demand and growing exports. China’s environmental regulations, however, lag far behind those of the U.S. and most of the developed world, and the Chinese battery industry has been responsible for at least 21 mass lead poisonings from 2009-2011, according to OK International. Imports of stationary lead batteries from Mexico have also doubled in the past ten years, although the environmental and occupational health regulations governing these manufacturing facilities are far weaker than in the U.S.

Although recycling is usually associated as beneficial to the environment, lead battery recycling in developing countries is generally one of the most hazardous industries. Most used lead batteries from the U.S. are recycled in domestic smelters, which have modernized in recent years to comply with environmental regulations. However, there has been a significant increase in the export of used lead batteries to Mexico for recycling. The New York Times recently reported on a study done by OK International and Fronteras Comunes revealing a 112 percent increase in exports of used lead batteries to Mexico from the U.S. between 2009 and 2010 following a lowering of the U.S. EPA standard for lead in ambient air in 2008 (see table 2). This trend is continuing with an additional 43 percent increase in the first 11 months of 2011.

Environmental regulations for lead battery recycling plants in Mexico are less stringent than those that apply to similar plants in the U.S. For example, the air standard for lead in Mexico is ten times the U.S. limit and the allowable occupational exposures are three times as high as in the U.S. (see table 1). In addition, weak enforcement of the standards in Mexico has lead to an even larger gap in environmental performance causing widespread lead exposure south of the border (see figure 3).


Most data center owner/operators work hard to be good corporate citizens. Many companies have social responsibility policies detailing how they intend to minimize toxic components in their products and recycle their e-waste. As large consumers of lead batteries, the data center community can play a significant role in improving the environmental performance of lead battery manufacturing and recycling in developing countries (see figures 4 and 5). The following outlines some simple steps that companies can take to improve the sustainability of their lead battery purchasing and recycling practices:

• Data center owner/operators should audit their suppliers and recyclers against industry specific environmental and occupational performance standards. Simply requiring compliance with local laws or that they have an environmental management system under ISO 14001 is insufficient for companies operating in emerging market countries.

• Data center owner/operators can require that their battery suppliers obtain certification under the Better Environmental Sustainability Targets (BEST) standard (see http://www.okinternational.org/lead-batteries/BEST-Standard). The BEST Standard is a comprehensive environmental program for lead battery plants, which covers lead emissions, occupational exposures, and a broad range of environmental performance criteria. Participating facilities are subject to annual audits against this performance standard to ensure independent verification.

• Include policies for end-of-life recycling of used lead batteries and pledge that they will not be shipped to countries with pollution standards and controls that are inferior to those in the U.S. Follow up on these efforts by tracking used battery shipments to determine their ultimate destination with a waste manifest system.

Lead batteries will remain an essential technology for backup power for the foreseeable future. Given the inherent risks in manufacturing and recycling lead batteries it is imperative that datacenter owner/operators develop policies and procedures for managing these hazards. Lead batteries should be prioritized in considering the health and environmental impacts in your supply chain.