Adult Blood Lead Epidemiology and Surveillance (ABLES)

Understanding Blood Lead Levels

Blood lead levels (BLLs) are measured by taking a blood sample. They indicate if a person was exposed to lead. By checking a worker’s blood lead level, occupational safety and health professionals can see if workers are protected from lead or not. In the cases where BLLs are elevated, evaluating these levels also helps healthcare providers decide on the best treatment.

BLL Reference Guide

There are several regulations and recommendations related to blood lead levels among workers.

Reference Blood Levels for Adults

0.92 µg/dL

In 2015-2016, this was the typical BLL among adults in the United States.1

5 µg/dL

Five µg/dL is the case classification ABLES uses to indicate an elevated BLL for surveillance purposes.3

If the BLL is between 5 to 9 µg/dL, California Department of Public Health (CDPH) recommends repeating BLLs every 3 months for adults until their BLL is less than 5 µg/dL.4

If pregnant, women should not exceed this level because the National Toxicology Program (NTP) concluded that mothers with BLLs even lower than this level can result in reduced fetal growth.2

The American College of Occupational and Environmental Medicine (ACOEM) also states it is inadvisable to allow pregnant workers, or those who are trying to or may become pregnant, continued exposure if BLL is >5 µg/dL and medical removal is recommended; pregnant workers may return to work when two repeat BLLs are <5 µg/dL.5

10 µg/dL

Below 10µg/dL, the NTP concluded lead increases blood pressure, the risk of hypertension, and the incidence of essential tremor.

ACOEM and CDPH recommend repeat BLL tests every two months if a person’s BLL results are between 10 to 19 µg/dL.6

15 µg/dL

Michigan Occupational Safety and Health Administration (MIOSHA) requires BLL testing every 2 months for employees found to have a BLL of 15 µg/dL or higher.

20 µg/dL

ACOEM and CDPH recommend medical removal if a worker has two consecutive BLLs between 20-29 µg/dL.

The American Conference of Governmental Industrial Hygienists (ACGIH®) guideline states that the typical worker can experience a BLL of 20 µg/dL without adverse health effect.7 This guideline is intended for use in the practice of industrial hygiene, but others may wish to use these guidelines as supplements to occupational safety and health programs.

25 µg/dL

ACOEM and CDPH recommend medical removal if a worker has two consecutive BLLs between 20-29 µg/dL.

The Occupational Safety and Health Administration (OSHA) considers a BLL of 25 µg/dL as serious and must be handled by inspection. This determination was based on OSHA’s National Emphasis Program (NEP) for Leadexternal icon, which was released to protect the health and safety of workers in industries determined to pose a higher risk to people and the environment.

30 µg/dL

MIOSHA requires medical removal at 30 µg/dL.

ACOEM and CDPH recommend that workers be medically removed from work with lead exposure if one BLL exceeds 30 µg/dL.

ACOEM, CDPH, and MIOSHA have issued more stringent and health protective limits than other federal and state-based regulatory groups.

40 µg/dL

If an employee has been medically removed from work based on a previously high BLL, OSHA permits the employee to return to work once 2 consecutive BLLs are measured below 40 µg/dL.

50-60 µg/dL

At a BLL of 50-60 µg/dL, OSHA requires medical removal.

The employer must remove any employees exposed to lead in the workplace if their BLL is 50 µg/dL or more for workers in construction, or 60 µg/dL or more for workers in general industry.

1 Centers for Disease Control and Prevention (CDC) [2019] Fourth national report on human exposure to environmental chemicals, updated tables, January 2019. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention  pdf icon

2 Association of Occupational and Environmental Clinics (AOEC) pdf icon[2007]external icon Medical management guidelines for lead-exposed adults, revised 4/24/2007pdf iconexternal icon. Washington, D.C.

California Department of Public Health [2019] Health-based guidelines for blood lead levels in adults 2019pdf iconexternal icon. Richmond, CA.

National Institute for Environmental Health Services (NIEHS) [2012] National Toxicology Program NTP Monograph: Health effects of low-level lead.  pdf iconexternal iconResearch Triangle Park, NC: U.S. Department of Health and Human Services, National Institutes of Health.

Holland MG, Cawthon D, American College of Occupational and Environmental Medicine (ACOEM) Task Force on Blood Lead Levels [2016] ACOEM position statement: Workplace lead exposurepdf iconexternal icon.  JOEM 58(12): e371-374.

3 Council of State and Territorial Epidemiologists (CSTE) [2015], Public health reporting and national notification for elevated blood lead levels.pdf iconexternal icon Atlanta, GA.

CDC [2016] National Notifiable Diseases Surveillance System (NNDSS), Lead, elevated blood lead level. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention.

California Department of Public Health Medical management of lead-exposed adultsexternal icon.  Sacramento, CA. Page last updated 11/19/2020.

4 California Department of Public Health [2019] Health-based guidelines for blood lead levels in adults 2019pdf iconexternal icon. Richmond, CA.5 Holland MG, Cawthon D, American College of Occupational and Environmental Medicine (ACOEM) Task Force on Blood Lead Levels [2016] ACOEM position statement: Workplace lead exposurepdf iconexternal icon.  JOEM 58(12): e371-374.

6 California Department of Public Health [2019] Health-based guidelines for blood lead levels in adults 2019pdf iconexternal icon. Richmond, CA.

Holland MG, Cawthon D, American College of Occupational and Environmental Medicine (ACOEM) Task Force on Blood Lead Levels [2016] ACOEM position statement: Workplace lead exposurepdf iconexternal icon.  JOEM 58(12): e371-374.

7 American Conference of Governmental Industrial Hygienists (ACGIH®) [Last revised April 2012]  Biological Exposure Indices (BEI®) Introductionexternal icon  Cincinnati, OH. Page visited 2/1/2021.

Page last reviewed: February 23, 2021