LEAD ACID BATTERIES AND ENVIROMENTAL REGULATIONS
To keep microscopic particles of airborne lead emissions to a minimum, manufacturers and recyclers use high efficiency air filters and wet scrubber to filter plant air before it is released to the atmosphere. The filters are inspected and replaced regularly. The filters also are equipped with alarms, and the process is shut down or re-routed should a filter tear or break.
Manufacturers and recyclers capture and treat process water to keep lead out of streams and rivers. The water is tested before it is released to be certain it meets clean water standards.
At recycling plants, air monitors are installed at the perimeter of each property to make sure any lead in the air is below the allowable limit. The limit is 1.5 micrograms of lead per cubic meter of air, averaged on a quarterly basis. Plants have a regular program of exterior vacuming or washing down paved areas and capturing and treating rainwater runoff. Vehicles that transport lead products typically are hosed down before leaving a facility so that any dust on tyres or vehicle body is not carried to public roads.
When taken together, all of these practices add up to a very responsible effort on the part of lead acid battery manufacturers and recyclers to keep even small amounts of lead out of the environment. These efforts make a measurable difference.
Lead acid batteries are the environmental success story of our time. Roughly 93% of all battery lead is recycled. Comparted to 42% of newspapers, 55% of aluminium soft drink and beer cans, and 40% of plastic soft drink bottles, lead acid batteries top the list of the most highly recycled consumer products.
The first process in recycling is the "breaking-up" of plastic and lead in old/used batteries. The lead grids, lead oxide and other lead parts are cleaned and melted together in smelting furnaces. The molten lead is poured into ingot moulds. Large ingots weighing about 1 ton are called hogs. Smaller ingots weighing 25kg are called pigs. After a few minutes the impurities otherwise known as dross, float to the top of the still molten lead in the ingot moulds. The dross is scraped away and the ingots are left to cool.
When the ingots are cool, they are removed from the moulds and sent to battery manufacturers, where they are re-melted and used in the production of new lead plates and other parts for new batteries.

Old battery acid can be handled in two ways:
The acid is neutralised with an industrial compound similar to household baking soda. This turns the acid into water. The water is treated, cleaned and tested to be sure it meets clean water standards. Then it is released into the public sewer system.
Another way to treat acid is to process it and convert it to calcium sulphate, an odourless white powder which is then dumped.
During the battery breaking process the container and lid are boken up into small pieces which are also recycled and when mixed with a small proportion of virgin material new plastic feed stock is produced and the cycle continues!