Medical surveillance guidelines

Under 1910.1025AppC employers must obtain blood lead tests at least every six months for employees exposed above the action level. The appendix explains that testing frequency increases to every two months for employees whose most recent blood lead was between 40 µg/100 g and the level requiring medical removal, and to monthly testing for employees who have been removed from exposure due to elevated blood lead.

• See the monitoring frequency table and discussion in Appendix C to 1910.1025 and the main standard at 1910.1025.

Yes. A zinc protoporphyrin (ZPP) test is required each time a blood lead measurement is obtained. The appendix specifically states that ZPP must be measured on every occasion a blood lead level is taken to help interpret exposure and possible effects.

• See the ZPP requirement in Appendix C to 1910.1025.

Under 1910.1025AppC an employer must offer an annual medical examination to any employee whose blood lead test within the previous 12 months was at or above 40 µg/100 g. The appendix also requires examinations before assigning an employee to an area where airborne lead meets or exceeds the action level and whenever the employee reports signs or symptoms of lead intoxication or requests medical advice about reproduction or respirator breathing problems.

• See the medical exam and consultation requirements in Appendix C to 1910.1025 and related provisions in 1910.1025.

Under 1910.1025AppC a worker must be medically removed when either (1) a blood lead level of 60 µg/100 g or greater is obtained and confirmed by a second blood test within two weeks, or (2) the average of the previous three blood lead determinations (or all determinations in the previous six months, whichever covers the longer period) equals or exceeds 50 µg/100 g, unless the last blood sample is 40 µg/100 g or less. Medical removal continues until return-to-work criteria are met.

• See the removal and averaging criteria in Appendix C to 1910.1025 and the main standard at 1910.1025.

Under 1910.1025AppC a removed employee may return when the medical criteria are met — typically when two consecutive blood lead levels are 40 µg/100 g or less or when a confirming blood lead level meets the return threshold for the phase-in period. The appendix explains that return-to-work is permitted when the physician indicates the worker is no longer at risk of material health impairment and specifies the numerical return criteria.

• See the return-to-work and removal continuation rules in Appendix C to 1910.1025 and 1910.1025.

Under 1910.1025AppC a blood lead level that meets the removal threshold must be confirmed by a second follow-up blood lead test within two weeks of the employer receiving the first test result. The appendix requires confirmation to avoid removing employees based on a single test result.

• See the confirmation timing requirement in Appendix C to 1910.1025.

Under 1910.1025AppC, until engineering and administrative controls achieve the permissible exposure limit, respirators must be used so that airborne lead exposure does not exceed 50 µg/m3 as an 8-hour TWA. The appendix makes clear respirators are required during the time controls are being phased in to meet the standard's exposure limits.

• See the respirator requirement and interim exposure guidance in Appendix C to 1910.1025 and 1910.1025.

Under 1910.1025AppC a physician's finding that an employee has a medical condition putting them at increased risk of material health impairment from lead exposure can trigger removal from exposure at or above the action level, or the physician may recommend special protective measures or exposure limitations. The appendix grants physicians flexibility to tailor protections, including for pregnant employees or those planning to conceive.

• See the physician authority and special protection provisions in Appendix C to 1910.1025 and 1910.1025.

Under 1910.1025AppC the employer must notify in writing each employee whose blood lead level exceeds 40 µg/100 g and inform them that the standard requires medical removal with medical removal protection benefits when levels exceed defined limits. The appendix describes this written notification and related employee information duties.

• See the employee notification requirement in Appendix C to 1910.1025 and the related employer obligations in 1910.1025.

Under 1910.1025AppC employees whose last blood lead level was less than 40 µg/100 g must have blood lead measured at least every six months. The appendix lays out the three-tiered frequency schedule based on previous blood lead results.

• See the monitoring frequency schedule in Appendix C to 1910.1025.

Under 1910.1025AppC employees who have been removed from lead exposure due to elevated blood lead must have blood lead measured monthly while removed. The appendix specifies monthly testing for removed employees to track recovery and determine return-to-work timing.

• See the monthly monitoring requirement for removed employees in Appendix C to 1910.1025.

Under 1910.1025AppC the employer must provide a medical examination as soon as possible after an employee reports signs or symptoms commonly associated with lead intoxication or requests medical advice concerning lead exposure and the ability to have a healthy child. The appendix lists these triggers for immediate medical evaluation.

• See the triggers for prompt medical examinations in Appendix C to 1910.1025.

Under 1910.1025AppC the examining physician may remove an employee from exposure or require special protective measures if the physician determines the employee is at risk of material health impairment; the employer must follow those medical recommendations, which may be more stringent than the standard. The appendix emphasizes the physician's broad flexibility to tailor protections to individual medical needs.

• See the physician authority provisions in Appendix C to 1910.1025 and 1910.1025.

Yes. Under 1910.1025AppC employers must ensure written medical opinions are prepared after each medical examination conducted pursuant to the standard. The appendix notes written medical findings, determinations, or opinions are part of the medical surveillance program and may drive removal or protective measures.

• See the written medical opinion requirement in Appendix C to 1910.1025 and 1910.1025.

Under 1910.1025AppC the appendix recommends periodic blood lead testing and zinc protoporphyrin (ZPP) measurements and describes other laboratory tests that can monitor lead’s effects and aid clinical interpretation; the appendix provides guidance on each test's value and limitations. Employers and physicians should follow the appendix's recommendations when designing surveillance testing panels.

• See the laboratory testing guidance and test descriptions in Appendix C to 1910.1025.

Under 1910.1025AppC a physician may recommend temporary medical removal or special protective measures for pregnant employees (or employees planning to conceive) if continued exposure at the current job poses a significant risk; the employer must implement those medical recommendations. The appendix acknowledges the physician's latitude to protect reproductive health.

• See the discussion of pregnant workers and physician recommendations in Appendix C to 1910.1025 and 1910.1025.

Under 1910.1025AppC workers removed because of elevated blood lead are allowed to return only when their blood lead meets the physician's return criteria, and the appendix lists industry-specific permissible airborne exposure limits without regard to respirator protection that applied during phased implementation; for removed workers the relevant final permissible airborne limit is 30 µg/m3 as an 8-hour TWA for many industries. The appendix table summarizes these allowable exposures tied to removal and return criteria.

• See Table 2 and the discussion of permissible airborne exposure limits for removed workers in Appendix C to 1910.1025.

Yes. Under 1910.1025AppC the appendix states OSHA's position on prophylactic chelation therapy is addressed as part of the medical surveillance guidance; employers and physicians should consult the appendix and the examining physician before considering chelation therapy because clinical judgment and confirmed laboratory results are necessary.

• See the appendix discussion that includes OSHA's position on chelation in Appendix C to 1910.1025.

Yes. Under 1910.1025AppC employers must provide respirators to meet the 50 µg/m3 exposure limit until engineering, work practice, and administrative controls have reduced airborne lead to the permissible levels without reliance on respirators. The appendix explicitly states respirators are required during the control-implementation period.

• See the respirator-use requirement during implementation in Appendix C to 1910.1025 and the standard at 1910.1025.

Yes. Under 1910.1025AppC the appendix explains that medical removal decisions may be based on the average of the last three blood lead determinations or the average of all determinations during the previous six months — whichever covers the longer time period — and that this average is used to determine if removal criteria (e.g., ≥50 µg/100 g average) are met, subject to the exception if the last sample is ≤40 µg/100 g.

• See the averaging and removal calculation guidance in Appendix C to 1910.1025.

The employer must maintain the worker's earnings, seniority, and other employment rights and benefits for up to 18 months during the period of medical removal. This economic protection helps workers participate meaningfully in medical surveillance and is described in 1910.1025 App C.

• Employers may condition this pay/protection on the employee's participation in medical surveillance.
• If an employee's blood lead does not decline within 18 months, the medical determination about further protection or removal is made case-by-case by a physician (see next question for details).

If an employee's blood lead level does not acceptably decline within 18 months, the situation is handled by an individual medical examination and the examining physician determines how best to protect that employee. See 1910.1025 App C.

• The physician will base the decision on lab values (blood lead, zinc protoporphyrin, blood counts, etc.) and clinical findings.
• The outcome can include continued removal, additional protective measures, or a finding that the employee cannot safely return to the former job.
• This is a rare, individualized situation and is not resolved by a fixed rule in the standard.

Yes. The examining physician may determine that an employee is incapable of ever safely returning to his or her former job status due to lead-related health impairment, and may specify additional removal time or permanent restrictions. This authority is described in 1910.1025 App C.

• If permanent restrictions are indicated, the employer must follow the physician's recommendations for protective measures or assignment changes.
• The standard also provides a formal multi-physician review process if the employee requests a second opinion (see next question).

If an employee wants a second opinion, the employee may see a physician of their choice; that second physician reviews the first physician's findings and may perform further exams or tests. If the two physicians disagree and cannot resolve their differences, they must jointly select a third physician to decide. This procedure is described in 1910.1025 App C.

• Employers must give the examining and consulting physicians specific information (see next question) to support accurate decisions.
• The three-physician process is intended to reach a final medical determination when opinions differ.

The employer must provide physicians with: a copy of the lead regulations and all appendices, a description of the employee's duties related to exposure, exposure levels to lead (and other toxic substances if relevant), a description of personal protective equipment used, blood lead levels, and all prior written medical opinions the employer has. These requirements are stated in 1910.1025 App C.

• Providing full exposure and job information helps physicians make an accurate medical determination about risk and necessary protections.
• Keep copies of what was provided in case of follow-up or dispute.

The employer must obtain a written medical opinion from the physician and provide it to the employee; this opinion must include blood lead levels, the physician's opinion on whether the employee is at risk of material impairment of health, any recommended protective measures if further exposure is allowed, and any recommended respirator limitations. See 1910.1025 App C.

• The written opinion helps the employer implement protections and informs the employee about health risk and any work limitations.
• Employers must follow any respirator-use limitations recommended by the physician.

No. Employers must instruct physicians not to reveal to the employer in writing or otherwise any findings, lab results, or diagnoses that are unrelated to occupational lead exposure. This confidentiality requirement is in 1910.1025 App C.

• Physicians must still advise employees about any medical conditions (occupational or non-occupational) that require further treatment or evaluation.
• This protects employee medical privacy while ensuring job-related health information is communicated.

No. The standard states that respirator use must not be used in lieu of temporary medical removal when an employee has elevated blood lead levels or is at risk of material health impairment. This prohibition is explained in 1910.1025 App C.

• Respirators may be used only as interim, supplementary, or short-term protection when engineering and work-practice controls are inadequate, and only if properly selected, fitted, maintained, and used.
• Reasons respirators are an imperfect substitute include fit difficulty, skin irritation, interference with vision/hearing/mobility, and breathing stress for some workers.

Respirators have limitations such as skin rash at the facepiece contact, added breathing stress for workers with cardiopulmonary problems, difficulty achieving an adequate fit, and interference with vision, hearing, or mobility—making them less reliable than engineering controls. These cautions are described in 1910.1025 App C.

• Respirators are useful only as temporary or supplementary protection and must be properly selected, fit-tested, cleaned, maintained, and worn.
• Respirator programs should not replace removal protection where temporary medical removal is indicated.

No. Prophylactic chelation (chelation given to prevent effects before they are necessary) is prohibited; diagnostic and therapeutic chelation are permitted only under a licensed physician's supervision with appropriate medical monitoring in an acceptable clinical setting. This policy is stated in 1910.1025 App C.

• The decision to start chelation must be individualized, based on symptoms, blood lead, ZPP, and other tests.
• Chelating agents like EDTA and penicillamine have significant side effects and should be justified by expected benefit.

Therapeutic chelation is generally not recommended unless frank and severe symptoms are present; removal from exposure and allowing the body to excrete lead naturally is preferred in many cases. This clinical guidance appears in 1910.1025 App C.

• EDTA and penicillamine can cause significant side effects, so benefits must outweigh risks.
• Chelation may be used diagnostically (e.g., CA-EDTA mobilization test) in limited cases to assess kidney involvement or mobile lead fraction.

Employers must maintain accurate records on exposure monitoring, medical surveillance, and medical removal for each employee. Exposure monitoring and medical surveillance records must be kept for 40 years or for the duration of employment plus 20 years, whichever is longer; medical removal records must be kept for the duration of employment. These recordkeeping requirements are stated in 1910.1025 App C.

• All required records must be made available upon request to the Assistant Secretary of Labor for Occupational Safety and Health and the Director of NIOSH.
• Accurate long-term records support worker health tracking and regulatory compliance.

Affected employees and former employees (or their authorized employee representatives) must have access to environmental and biological monitoring and medical removal records. Employees or their designated representatives have access to their entire medical surveillance records. This access requirement appears in 1910.1025 App C.

• Employers should establish procedures to provide these records promptly upon request.
• Maintaining confidentiality for non-occupational medical findings remains required (see physician confidentiality rules).

Employers must inform all workers exposed to lead at or above the action level about the provisions of the lead standard and all appendices, the purpose and description of medical surveillance, and the provisions for medical removal protection if temporary removal is required. This worker information requirement is stated in 1910.1025 App C.

• Employees should understand potential health effects of lead, the surveillance program, and their rights under the standard.
• Clear worker education increases participation in monitoring and helps protect health.

OSHA based protections on two medical judgments: to prevent adverse health effects over a working lifetime, workers' blood lead levels should be maintained at or below 40 µg/100 g, and workers who intend to parent in the near future should be kept below 30 µg/100 g to minimize reproductive risks. These judgments are described in 1910.1025 App C.

• OSHA focused on pathophysiological changes and later disease stages when setting these levels.
• Physicians are encouraged to stay current on reproductive research to advise pregnant workers or those planning to conceive.

OSHA describes early effects on heme synthesis enzymes: inhibition of delta-aminolevulinic acid dehydratase (ALA-D) occurs at blood lead below 20 µg/100 g, and significant ALA-D inhibition occurs in more than 20% of people at 40 µg/100 g. Inhibition of ferrochelatase raises free erythrocyte protoporphyrin (FEP) and zinc protoporphyrin (ZPP); nearly 100% of people have increased FEP at 50 µg/100 g, and ZPP increases exponentially above 40 µg/100 g. See 1910.1025 App C.

• These biochemical changes are treated as early stages of disease that can progress if exposure continues.
• ZPP screening is useful because ZPP levels correlate with higher blood lead levels.

Lead-induced inhibition of heme synthesis can eventually cause anemia; lead-associated decreases in hemoglobin have been observed at blood lead levels as low as 50 µg/100 g, while most lead-induced anemias occur at levels above 80 µg/100 g. This explanation appears in 1910.1025 App C.

• Anemia from lead can be asymptomatic when mild but may cause dizziness, fatigue, and rapid heartbeat when severe.
• Laboratory findings can include reticulocytosis, basophilic stippling, and ringed sideroblasts (though none are uniquely diagnostic of lead).

OSHA states that central and peripheral nervous system effects can occur; early CNS symptoms include irritability, sleep problems, fatigue, headache, tremor, and poor memory, and overt symptoms are more likely at blood lead levels of about 60 µg/100 g and above. These health effects are described in 1910.1025 App C.

• Severe acute encephalopathy can occur after large exposures and may be rapidly life-threatening.
• Peripheral motor neuropathy can occur, with slowing of motor nerve conduction detectable at levels as low as 50 µg/100 g.

ZPP testing is used as a screening tool because ZPP rises as ferrochelatase is inhibited by lead; ZPP increases markedly at higher blood lead levels and has been developed as a screening test for lead exposure. This is explained in 1910.1025 App C.

• ZPP is most useful at higher blood lead levels (e.g., above 40 µg/100 g) where ZPP rises exponentially.
• ZPP alone is not a definitive diagnostic test but is valuable as part of surveillance along with blood lead measurements.

Yes. The guidance states that MRP benefits during removal may be conditioned upon participation in medical surveillance. See 1910.1025 App C.

• Conditioning benefits on surveillance participation encourages employees to comply with monitoring that protects their health.
• Any conditions should be applied fairly and documented in company policies.

If the first and second physicians cannot resolve their disagreement, they must designate a third physician to resolve the dispute; the process and requirements for physician review are set out in 1910.1025 App C.

• Employers must ensure physicians have the required exposure and job information to make an informed determination.
• The third physician's determination is intended to be the final medical decision in the dispute resolution process.

A physician should base the medical determination on laboratory values (blood lead levels, ZPP, blood counts, and other warranted tests) and clinical judgment about symptoms or exam findings attributable to lead toxicity. This decision-making framework is described in 1910.1025 App C.

• The physician may recommend continued removal, additional protective measures, or permanent restrictions depending on test results and clinical findings.
• The physician's judgment is key where blood lead does not decline as expected within removal periods.

The main clinical signs are painless extensor muscle weakness of the fingers and hand—progressing in severe cases to wrist drop and, less commonly, foot drop. OSHA’s guidance in 1910.1025AppC describes these motor deficits and notes associated electromyographic changes (reduced motor unit potentials, increased duration, fibrillations, fasciculations) seen at higher blood lead levels.

• Check strength of extensor muscle groups (especially finger/hand extensors) and look for wrist drop.
• Perform a detailed peripheral nerve exam including sensory testing, reflexes, gait, coordination, and tremor.
• Remember that recovery is often incomplete; 1910.1025AppC explains neuropathies may be only partially reversible, likely because of segmental demyelination.

The medical evaluation must include blood lead level; hemoglobin and hematocrit with red cell indices and peripheral smear; blood urea nitrogen; serum creatinine; routine urinalysis with microscopy; and a zinc protoporphyrin (ZPP) level. OSHA’s list appears in 1910.1025AppC.

• The physician may order additional tests as clinically indicated (for example, delta-ALA, coproporphyrin, dark-field for basophilic stippling, reticulocyte count, iron studies, or bilirubin) because the standard authorizes further testing "in accordance with sound medical practice." See 1910.1025AppC.

Nerve conduction studies should be ordered when a peripheral neuropathy is suspected, and a 24‑hour creatinine clearance (or other measures of glomerular filtration) should be ordered when renal disease is suspected. 1910.1025AppC explicitly recommends these tests for diagnosis and monitoring.

• Nerve conduction studies help confirm neuropathy and provide a baseline to follow therapy.
• A 24‑hour urine for creatinine clearance, protein, and electrolytes can detect early renal impairment before serum creatinine or BUN rise.
• The physician may also choose other GFR measurements if clinically appropriate, as the guidance notes that BUN/creatinine rise only after substantial loss of kidney function.

Lead exposure can impair fertility in both men and women and increase risks to pregnancy and the fetus; OSHA recommends maintaining blood lead concentrations at or below 30 ug/100 g for workers who wish to bear children. The recommendation appears in 1910.1025AppC.

• In men, lead can reduce libido, cause impotence, lower sperm count and quality (teratospermia, hypospermia, asthenospermia) and sterility; teratospermia has been noted at mean blood lead of 53 ug/100 g and other sperm changes around 41 ug/100 g.
• In women, lead exposure can cause menstrual disturbances, increased sterility, premature births, miscarriages, and stillbirths; lead crosses the placenta from about 12–14 weeks onward.
• The guidance supports a 30 ug/100 g maximum permissible blood lead level in both males and females who wish to bear children to reduce reproductive and fetal risk.

OSHA states that blood lead levels of 50–60 ug/100 g in children can cause significant neurobehavioral impairments and that hyperactivity may be seen at levels as low as 25 ug/100 g; OSHA recommends keeping children and fetuses below 30 ug/100 g with a population mean of 15 ug/100 g. These points are in 1910.1025AppC.

• OSHA recommends a maximum of 30 ug/100 g for children and fetuses and a population mean near 15 ug/100 g.
• Because lead crosses the placenta, maternal and fetal blood lead levels are comparable at birth, so protecting pregnant workers helps protect the fetus.

No — the gum (Burtonian) lead line is not a reliable sign because it may be absent even in severe lead poisoning if the person practices good oral hygiene. 1910.1025AppC explicitly notes the lead line can be missing despite severe toxicity.

• Do not rely on the gingival lead line alone; perform a full history, symptom review, physical exam, and the required laboratory testing (blood lead, ZPP, hematology, renal tests) in suspected cases.
• A normal oral exam should not delay further evaluation when other signs or exposures suggest lead toxicity.

A complete work history and non-occupational exposure history must be obtained, including previous jobs, processes, exposure to fumes/dust, respiratory protection, personal hygiene, smoking/eating at work, laundry of work clothes, and hobbies that involve lead. 1910.1025AppC emphasizes detailed employment and medical histories for evaluating lead toxicity.

• Include past and current medical conditions, medications, surgeries, allergies, smoking and alcohol use, childhood lead exposures, and reproductive history.
• Specifically ask about hobbies (e.g., hunting, casting bullets, stained-glass work) and household contacts that could cause non-occupational lead exposure.
• Good documentation of workplace processes and past medical surveillance helps assess long‑term risks like neurotoxicity and nephrotoxicity.

A pregnancy test or laboratory evaluation of male fertility must be included in the evaluation if requested by the employee, and the physician is also authorized to order additional tests as dictated by clinical judgment. 1910.1025AppC states these are part of the permitted and required components of the medical evaluation.

• The standard allows the physician to order any further laboratory or other tests "deemed necessary in accordance with sound medical practice."
• Employers and clinicians should ensure informed consent and confidentiality for pregnancy and fertility testing, and follow applicable medical privacy rules while addressing lead-related reproductive risks.