Lead - Overview | Occupational Safety and Health Administration (2024)

Overview

Inorganic lead is a malleable, blue-gray, heavy metal that occurs naturally in the Earth’s crust. Lead was one of the first metals used by humans and consequently, the cause of the first recorded occupational disease (lead colic in a 4th century BC metal worker). In 2018, U.S. production of lead was estimated at 1.3 million metric tons; primarily from secondary refining of scrap metal (lead-acid batteries) and 10 mines mostly in Alaska and Missouri. U.S. mines produced 260,000 metric tons, ranking fourth in the world behind China, Australia, and Peru. The U.S. has become more reliant on imported refined lead in recent years owing to the closure of the last primary lead smelter in 2013. The U.S. has 11 operating secondary smelters (7 companies) accounting for 99% of refined lead production in the U.S. Lead can be used as a pure metal, combined with another metal to form an alloy, or in the form of a chemical compound. The primary use of lead in the U.S. is for automotive lead-acid storage batteries, a type of rechargeable electric battery which uses an almost pure lead alloy. Lead-formed alloys are typically found in ammunition, pipes, cable covering, building material, solder, radiation shielding, collapsible tubes, and fishing weights. Lead is also used in ceramic glazes and as a stabilizer in plastics. There is an estimated 6.1 million lead pipe service lines for potable water systems still in use in the U.S. creating the potential for lead exposure in drinking water and prompting the U.S. Environmental Protection Agency to work with states and communities to modernize the outdated water infrastructure. Lead was used extensively as a corrosion inhibitor and pigment in paints but concerns over its toxicity led to the CPSC in 1977 to ban the use of lead in paint for residential and public buildings. Prior to the mid-1980s, the organic lead compounds tetramethyl lead and tetraethyl lead were used as an antiknock additive and octane booster in gasoline but environmental exposure concerns resulted in the gradual phase-out of leaded gasoline in the United States. Organic lead compounds continue to be used in high octane fuel in the aviation industry for piston engine aircraft.

Lead enters the body primarily through inhalation and ingestion. Today, adults are mainly exposed to lead by breathing in lead-containing dust and fumes at work, or from hobbies that involve lead. Lead passes through the lungs into the blood where it can harm many of the body's organ systems. While inorganic lead does not readily enter the body through the skin, it can enter the body through accidental ingestion (eating, drinking, and smoking) via contaminated hands, clothing, and surfaces. Workers may develop a variety of ailments, such as neurological effects, gastrointestinal effects, anemia, and kidney disease. See the Health Effects section of this webpage for more information.

Employers are required to protect workers from inorganic lead exposure under OSHA lead standards covering general industry (1910.1025), shipyards (1915.1025), and construction (1926.62). The lead standards establish a permissible exposure limit (PEL) of 50 μg/m³ of lead over an eight-hour time-weighted-average for all employees covered. The standards also set an action level of 30 μg/m³, at which an employer must begin specific compliance activities, including blood lead testing for exposed workers. The lead standards also include ancillary provisions such as medical surveillance, exposure monitoring, and hygiene facilities and practices that are critical in preventing lead exposure and elevated blood lead levels. For more information on lead standard requirements go to the Standards section of this webpage.

Who is Exposed to Lead?

Workers are exposed to lead as a result of the production, use, maintenance, recycling, and disposal of lead material and products. Lead exposure occurs in most industry sectors including construction, manufacturing, wholesale trade, transportation, remediation and even recreation.

Construction workers are exposed to lead during the removal, renovation, or demolition of structures painted with lead pigments. Workers may also be exposed during installation, maintenance, or demolition of lead pipes and fittings, lead linings in tanks and radiation protection, leaded glass, work involving soldering, and other work involving lead metal or lead alloys. In general industry, workers come in contact with lead in solder, plumbing fixtures, rechargeable batteries, lead bullets, leaded glass, brass, or bronze objects, and radiators. Lead exposure can occur not only in the production of these kinds of objects but also in their use (e.g., firing ranges), repair (e.g., radiator repair), and recycling (e.g., lead-acid battery recycling).

In the general population, lead may be present in small but hazardous concentrations in food, water, and air. Lead poisoning from deteriorating old paint is the primary source of elevated blood lead levels in children. Children under the age of six are at risk of developing cognitive health effects even at very low blood lead levels. Pregnant women or those who might become pregnant must avoid lead exposure because it is toxic to the fetus. Another source of environmental exposure to lead is from workers who take home lead dust on their clothing and shoes.

Where Does Exposure to Lead Occur?

Lead is an important metal for many types of businesses and industrial processes. Lead is most often used in the manufacturing sector (e.g., manufacturing products containing lead) but worker exposure can also occur in other industry sectors including construction and wholesale trade. OSHA provides a publicly available Chemical Exposure Health Database which includes industrial hygiene sample results taken by OSHA field personnel during site visits. These data can provide a snapshot of industry sectors and business subcategories where lead air concentrations have been found. The industry profile tables in this website are based on lead samples taken during OSHA inspections in the last 5 years of available data. While the tables represent only a small fraction of the total number of companies in their respective industries, the results can provide insight into where workplace lead exposure is occurring in the United States.

Another source for identifying where lead exposure occurs at work is the NIOSH Adult Blood Epidemiology & Surveillance (ABLES) program. ABLES currently has 30 states participating in the collection of elevated blood lead levels in adults. This program identifies industries and occupations where workplace exposure to lead is occurring.

Related topic: Toxic Metals - Safety and Health Topics Page

Disclaimer: The information and resources provided on this web page are for informational purposes only and not intended as an endorsem*nt by OSHA of its contents, products, methods, or services.