Lead and Arsenic in Glass Beads
RESTRICTIONS IN ABRASIVE BLASTING BACKGROUND
Abrasive blasting, commonly known as sandblasting—blowing various types of media out of a nozzle usually with compressed air—is a useful (and common) industrial technique for preparing surfaces for a variety of purposes. Small glass beads are one type of loose abrasive used with blasting equipment for surface preparation including cleaning, finishing, deburring and peening. Small glass beads are used in a diverse variety of blasting applications, such as removing residues from automobile parts or calcium deposits from swimming pools. The blasting process is done in the open, within special containment facilities, or within blasting cabinets. Like any glass, the composition of these beads can vary.
Some glass beads have been found to contain toxic metals like lead and arsenic. This is a concern because the beads are typically pulverized during use and generate dust. Lead- or arsenic-containing dust can be inhaled or ingested, thereby exposing those performing the sandblasting, as well as other people in the vicinity. This dust can also easily be disbursed onto land or into air and water, potentially contaminating the surrounding environment and ultimately harming people and wildlife.
Arsenic is recognized as a carcinogen and developmental toxicant. Arsenic exposure can increase the risk of skin, lung and possibly lymphatic cancers, and lead to peripheral neuropathy and vascular disease. Lead is recognized as a carcinogen, and as both a developmental and reproductive toxicant. Lead exposure can cause peripheral neuropathy, anemia, kidney damage, increased blood pressure, male sterility and increased risk of cancer.
RECENT LEGISLATION (AB 1930)
Starting January 1, 2011, California law (as found in Health and Safety Code section 25258) prohibits the manufacturing, selling, offering for sale, or offering for promotional purposes glass beads that contain more than 75 parts per million (ppm) of arsenic or 100 parts per million (ppm) of lead by weight if the beads will be used with pressure, suction or wet- or dry-type blasting equipment. These restrictions were enacted by the Legislature in Assembly Bill (AB) 1930 (stats. 2010, ch. 368), which added article 16 to chapter 6.5 in Division 20 of the Health and Safety Code (Health and Safety Code sections 25258 through 25258.2). These restrictions will sunset on January 1, 2015.
For the full text of the bill read Assembly Bill 1930 (AB 1930)
Health and Safety Code section 25258, also requires each container or bag of glass beads sold in California for surface preparation and that will be used with particular types of blasting equipment to be labeled with the following statement:
“Glass bead contents contain less than 75 ppm arsenic and less than 100 ppm lead pursuant to the California Health and Safety Code Section 25258.”
The testing methods for determining the weight percentage of arsenic and lead are EPA Method 3052 (with certain allowable modifications) and EPA Method 6010C as specified in EPA Test Methods for Evaluating Solid Waste, Physical/Chemical Methods, SW-846 (Third Edition, as currently updated). In addition to these methods, a generally accepted instrumental method with traceable standards may be used, including X-ray fluorescence (XRF) spectroscopy.