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Course 854 - Lead Safety in Construction

Safety guides and audits to make your job as a safety professional easier

Lead Basics

A cranes outrigging supported in muddy conditions.
Demolition may expose workers to lead dust.

What is Lead?

Lead is a cumulative and persistent toxic substance that poses a serious health risk. It is a naturally occurring element found in small amounts in the earth’s crust. While lead does has some beneficial uses, it can be toxic to humans and animals, causing health effects. Below is a description of the characteristics, uses, and Permissible Exposure Limit (PEL), and Action Level (AL) for lead:

  • Substance: Pure lead (Pb) is a heavy metal at room temperature and pressure and is a basic chemical element. It can combine with various other substances to form numerous lead compounds.
  • Compounds Covered by 1926.62, Lead: The word "lead" when used in this standard means elemental lead, all inorganic lead compounds and a class of organic lead compounds called lead soaps. The standard does not apply to other organic lead compounds.
  • Uses: Exposure to lead occurs in at least 120 different occupations, including primary and secondary lead smelting, lead storage battery manufacturing, lead pigment manufacturing and use, solder manufacturing and use, shipbuilding and ship repairing, auto manufacturing, and printing. Since 1978, lead has not been allowed in house paint due to health concerns.
  • Permissible Exposure: The Permissible Exposure Limit (PEL) set by the standard is 50 micrograms of lead per cubic meter of air (50 ug/m(3)), averaged over an 8-hour workday.
  • Action Level: The standard establishes an action level of 30 micrograms per cubic meter of air (30 ug/m(3)), time weighted average, based on an 8-hour work-day. The action level initiates several requirements of the standard, such as exposure monitoring, medical surveillance, and training and education.

Click on the button below to see a video giving you an overview lead and its health effects.

We encourage you to visit the NIOSH Pocket Guide to Chemical Hazards - Lead webpage that contains chemical and physical properties and other information on lead.

Read the material in each section to find the correct answers to each of the questions. After answering all questions, click the "Check Quiz Answers" button to see your score and a list of missed questions. To correct a question, return to the question, review the material, change your answer, and return to the last section page. Click the "Check Quiz Answers" again to recheck the results.

Do not refresh these pages or you'll have to answer all questions again.

Note: Videos and exercises in our courses are for information only and not required to view. Final exam questions will not be derived from the videos. OSHAcademy is not responsible for video content.

1. Lead should NOT be found in ____.

a. ammunition
b. pipes
c. batteries
d. new house paint

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Who is at Risk?

Although the focus of the course is on employees working in construction, it's important to understand that lead hazards can also affect each employee's family. With that in mind, we'll cover the effects of lead exposure on children as well as adults.

A cranes outrigging supported in muddy conditions.
Lead can affect the entire family.


Lead is particularly dangerous to children because their growing bodies absorb more lead than adults do and their brains and nervous systems are more sensitive to the damaging effects of lead. Babies and young children can also be more highly exposed to lead because they often put their hands and other objects that can have lead from dust or soil on them into their mouths. Children may also be exposed to lead by eating and drinking food or water containing lead or from dishes or glasses that contain lead, inhaling lead dust from lead-based paint or lead-contaminated soil or from playing with toys with lead paint. See more.

Adults, Including Pregnant Women

Adults may be exposed to lead by eating and drinking food or water containing lead or from dishes or glasses that contain lead. They may also breath lead dust by spending time in areas where lead-based paint is deteriorating, and during renovation or repair work that disturbs painted surfaces in older homes and buildings. Working in a job or engaging in hobbies where lead is used, such as making stained glass, can increase exposure as can certain alternative (folk) remedies containing lead. A pregnant woman’s exposure to lead from these sources is of particular concern because it can result in exposure to her developing baby.

Click the button below to learn more about the hazards of lead exposure at home.

2. Why is exposure to lead more dangerous for children than adults?

a. Lead moves more slowly through a child's body
b. Children absorb more lead than adults
c. Children breath more rapidly than adults
d. Children chew on lead-containing objects

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Sources of Lead

Older Homes and Buildings

A cranes outrigging supported in muddy conditions.
Lead dust is common in windows, doors, and soil.

Lead paint is still present in millions of structures, sometimes under layers of newer paint. If the paint is in good shape, the lead paint is usually not a problem. Deteriorating lead-based paint (peeling, chipping, chalking, cracking, damaged, or damp) is a hazard and needs immediate attention.

If a building was built before 1978, there is a good chance it has lead-based paint. In 1978, the federal government banned consumer uses of lead-containing paint, but some states banned it even earlier. Lead from paint, including lead-contaminated dust, is one of the most common causes of lead poisoning. The older the structure, the more likely lead is present. About 24% of homes built between 1960-1977 contain lead. The number of homes containing lead increases to about 87% of all homes built prior to 1940.

Then click on the buttons below to see a list of additional sources of lead exposure and videos produced by the Wisconsin Department of Public Health discusses exterior and interior renovation practices. .

  • Windows and window sills;
  • Doors and door frames;
  • Stairs, railings, banisters, and porches.
  • Lead in household dust results from indoor sources such as deteriorating lead-based paint.
  • Lead dust can also be tracked into a structure from soil outside that is contaminated by deteriorated exterior lead-based paint and other lead sources, such as industrial pollution and past use of leaded gasoline.
  • Renovation, repair or painting activities can create toxic lead dust when painted surfaces are disturbed or demolished. Learn more about hiring lead-safe certified contractors.
  • Pipes and solder - Lead is used in some water service lines and household plumbing materials. Lead can leach, or enter the water, as water flows through the plumbing. Lead pipes and lead solder were commonly used until 1986.
  • Flame-torch cutting, welding, the use of heat guns, sanding, scraping and grinding of lead painted surfaces in repair, reconstruction, dismantling and demolition work;
  • Abrasive blasting of bridges and other structures containing lead-based paints;
  • Use of torches and heat guns, and sanding, scraping and grinding lead-based paint surfaces during remodeling or abating lead-based paint; and
  • Maintaining process equipment or exhaust duct work.

3. Consumer uses of lead-based paint was banned by the federal government in _____.

a. 2000
b. 1978
c. 1966
d. 1940

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Lead Dust

Track of a front end loader.
When old structures are demolished, exposure to lead dust is likely.

Lead in dust results from indoor sources such as:

  • old lead paint on surfaces that are frequently in motion or bump or rub together (such as window frames),
  • deteriorating old lead paint on any surface,
  • repair activities,
  • tracking lead contaminated soil from the outdoors into the indoor environment, or
  • lead dust on clothing worn at a job site.

Exposure to lead dust is common when old buildings are demolished. Even in well-maintained buildings, lead dust can form when lead-based paint is scraped, sanded or heated during home repair activities. Lead paint chips and dust can get on surfaces and objects that people touch. Settled lead dust can re-enter the air when the building is vacuumed or swept, or people walk through it.

To reduce exposure to lead dust, it is especially important to maintain all painted surfaces in good condition, and to clean frequently, to reduce the likelihood of chips and dust forming. Using a lead-safe certified renovator to perform renovation, repair and painting jobs is a good way to reduce the likelihood of contaminating your home with lead-based paint dust.

Click on the button below to learn more about the hazards of lead exposure in various workplaces.

4. Lead-based paint can become hazardous when it is _____.

a. cleaned frequently
b. covered with new paint
c. scraped, sanded, or heated
d. taped over with a plastic covering

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Construction Workers and Exposure

How Lead is Used

A cranes outrigging supported in muddy conditions.
Abrasive blasting protective measures.

In construction, lead is used frequently for roofs, cornices, tank linings, and electrical conduits. In plumbing, soft solder, used chiefly for soldering tinplate and copper pipe joints, is an alloy of lead and tin. Soft solder has been banned for many uses in the United States.

  • The Consumer Product Safety Commission bans the use of lead-based paint in residences.
  • Lead continues to be used on bridges, railways, ships, lighthouses, and other steel structures because lead-based paint inhibits the rusting and corrosion of iron and steel.

Construction projects vary in their scope and potential for exposing workers to lead and other hazards. Projects such as removing paint from a few interior residential doors may involve limited exposure. Others projects, however, may involve removing or stripping substantial quantities of lead-based paints on large bridges and other structures.

Workers potentially at risk for lead exposure include those involved in iron work; demolition work; painting; lead-based paint abatement; plumbing; heating and air conditioning maintenance and repair; electrical work; and carpentry, renovation, and remodeling work.

Plumbers, welders, and painters are among those workers most exposed to lead. Significant lead exposures also can arise from removing paint from surfaces previously coated with lead-based paint such as bridges, residences being renovated, and structures being demolished or salvaged. With the increase in highway work, bridge repair, residential lead abatement, and residential remodeling, the potential for exposure to lead-based paint has become more common.

Click on the button below to see a list of the those occupations at most risk of lead exposure.

Workers at the highest risk of lead exposure are those involved in:

  • Abrasive blasting, and
  • Welding, cutting, and burning on steel structures.

Other operations with the potential to expose workers to lead include:

  • Lead burning;
  • Using lead-containing mortar;
  • Power tool cleaning without dust collection systems;
  • Rivet busting;
  • Cleanup activities where dry expendable abrasives are used;
  • Movement and removal of abrasive blasting enclosures;
  • Manual dry scraping and sanding;
  • Manual demolition of structures;
  • Heat-gun applications;
  • Power tool cleaning with dust collection systems; and
  • Spray painting with lead-based paint.

Click on the button below to see a video on lead-based paint renovation and abatement.

5. Workers at the highest risk of exposure to lead are involved in _____.

a. power tool cleaning and spray painting
b. rivet busting and manual dry scraping
c. cleanup activities and demolition
d. abrasive blasting and welding

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Cutting concrete creating dust
Primary route for dust is inhalation.

Entry Routes

Exposure to lead and lead chemicals can occur through four routes: ingestion, inhalation, dermal absorption, and trans-placental (endogenous) routes.

The two primary entry routes into the body for lead are ingestion (eating) and inhalation (breathing). A third, less significant entry route is through dermal (skin) absorption. Only certain organic lead compounds are absorbed through your skin.

When lead is scattered in the air as a dust, fume or mist it can be inhaled and absorbed through you lungs and upper respiratory tract. Inhalation of airborne lead is generally the most important source of occupational lead absorption. You can also absorb lead through your digestive system if you handle contaminated items or handle them with hands contaminated with lead.

Click on the buttons below for more information on each of these exposure routes.

Lead exposure in the general population (including children) occurs primarily through ingestion, making it the route that most commonly leads to elevated blood lead levels (BLLs). This includes swallowing a foreign body containing lead (i.e., jewelry, etc.).

From 20% to 70% of ingested lead is absorbed into the body, (with children generally absorbing a higher percentage than adults).

  • Lead paint is the major source of higher lead level exposures in children in the United States as it:
    • deteriorates,
    • peels,
    • chips,
    • is removed (e.g., during renovation), or
    • crumbles due to friction.
  • Lead poisoning also occurs due to the ingestion of contaminated
    • food,
    • water,
    • alcohol, or
    • folk or home remedy medicines.
  • When fine particulate lead is inhaled, it can be absorbed directly through the lungs or could also be carried to the throat where it can be swallowed and absorbed.

Inhalation is the second major pathway of exposure for the general population in the United States. The amount absorbed from the respiratory system depends on particle size, respiratory volume, amount of deposition, and the mucociliary clearance of the inhaled lead.

  • Almost all inhaled lead is absorbed into the body (with children generally absorbing a higher percentage than adults, as they have a higher respiratory frequency).
  • Since leaded gasoline additives were phased out beginning in the 1970s and control measures were implemented in industries to reduce air emissions, inhalation from these sources is no longer the major exposure pathway to lead for the general population in the United States.
  • Leaded gasoline is still used in only a handful of countries, but the resulting emissions pose a major public health threat.
  • Inhalation may be the primary route of exposure for some workers in industries that involve lead.
  • Inhalation may be the primary route of exposure for adults involved in home renovation activities, and hobbies like lead glass making, stained glass making/soldering.
  • Lead is a component of tobacco and tobacco smoke, and smokers have higher blood lead levels (BLLs) than do nonsmokers.
  • Second hand smoke may contribute to increased BLLs in U.S. children. Lead dust concentrations, usually ingested during hand to mouth activity, do not appear to mediate this association, suggesting inhalation of second hand smoke is a major pathway of exposure.
  • Eliminating second hand smoke exposure may reduce lead exposure in children.

Dermal exposure does play a role for exposure to organic lead among workers, but is not considered a significant pathway for the general population.

  • Organic lead may be absorbed directly through the skin.
  • Organic lead (tetraethyl lead) is more likely to be absorbed through the skin than inorganic lead.
  • Dermal exposure is most likely among people who work with lead or materials that contain lead.

Endogenous exposure to lead may contribute significantly to an individual's current BLL. Numerous reports document lead poisoning resulting from retained bullet or shrapnel fragments; thus, a history of military or other penetrating trauma may be important. If in a pregnant woman, this poses a particular risk to the developing fetus. Trans-placental exposure to the unborn child can happen if the mother is exposed to lead.

  • Once absorbed into the body, lead may be stored for long periods in mineralizing tissue (e.g., teeth and bones).
  • The stored lead may be released again into the bloodstream, especially in times of calcium stress (e.g., pregnancy, lactation, osteoporosis) or calcium deficiency.

Acute and Chronic Exposure

There is no sharp dividing line between rapidly developing acute effects of lead, and chronic effects which take longer to acquire. Lead adversely affects numerous body systems, and causes forms of health impairment and disease which arise after periods of exposure as short as a few days or as long as several years.

Acute, short-term overexposure. Lead is a potent, systemic poison that serves no known useful function once absorbed by your body. Taken in unusually large doses, lead can kill you in a matter of days.

Chronic, long-term overexposure. Long-term overexposure can lead to severe damage to your blood-forming, nervous, urinary and reproductive systems.

Click on the button below to watch a video on why lead is so bad for humans.

6. Lead can cause health impairment and disease after periods of exposure as short as a few _____.

a. hours
b. days
c. months
d. years

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Signs and Symptoms

A significant portion of the lead that you inhale or ingest gets into your blood stream. Once in your blood stream, lead circulates throughout your body and is either filtered out of the body or stored in various organs and body tissues. As exposure to lead continues, the amount stored in your body will increase. Even though you may not be aware of any immediate symptoms of disease, stored lead can be slowly causing irreversible damage to cells, organs, and body systems.

Click on the button below to see the list of symptoms of chronic overexposure to lead and more information on .

Encephalopathy. Damage to the central nervous system in general and the brain (encephalopathy) in particular is one of the most severe forms of lead poisoning. The most severe, often fatal, form of encephalopathy may be preceded by vomiting, a feeling of dullness progressing to drowsiness and stupor, poor memory, restlessness, irritability, tremor, and convulsions. It may arise suddenly with the onset of seizures, followed by coma, and death.

Peripheral neuropathy. There is also a tendency for muscular weakness to develop. This weakness may progress to paralysis often observed as a characteristic "wrist drop" or "foot drop" and is a manifestation of a disease to the nervous system called peripheral neuropathy.

Kidney disease. Chronic overexposure to lead also results in kidney disease with few, if any, symptoms appearing until extensive and most likely permanent kidney damage has occurred. When overt symptoms of urinary dysfunction arise, it is often too late to correct or prevent worsening conditions, and progression to kidney dialysis or death is possible.

Reproductive systems. Chronic overexposure to lead impairs the reproductive systems of both men and women. Overexposure to lead may result in decreased sex drive, impotence and sterility in men. Lead can alter the structure of sperm cells raising the risk of birth defects. There is evidence of miscarriage and stillbirth in women whose husbands were exposed to lead or who were exposed to lead themselves. Lead exposure also may result in decreased fertility, and abnormal menstrual cycles in women.

Anemia. Overexposure to lead also disrupts the blood-forming system resulting in decreased hemoglobin (the substance in the blood that carries oxygen to the cells) and ultimately anemia. Anemia is characterized by weakness, pallor and fatigue as a result of decreased oxygen carrying capacity in the blood.


Each employee is responsible for reporting signs and symptoms of health problems. You should notify your employer if you:

  • develop signs or symptoms associated with lead poisoning, or
  • desire medical advice concerning the effects of current or past exposure to lead on your ability to have a healthy child.
  • have difficulty breathing during a respirator fit test or while wearing a respirator.

In each of these cases your employer must make available to you appropriate medical examinations or consultations. These must be provided at no cost to you and at a reasonable time and place.

Measuring Lead Levels

blood specimens
Keep lead levels below 40ug/100g to be safe.

Measuring your blood lead level is the most useful indicator of the amount of lead being absorbed by your body. Blood lead levels (PbB) are most often reported in milligrams (mg) or micrograms (ug) of lead (1 mg=1000 ug) per 100 grams (100g).

  • Although there is NO established absolutely safe level of lead exposure, the best way to prevent all forms of lead-related impairments and diseases-both short term and long term- is to maintain your blood PbB below 40 ug/100g. Once your blood lead level climbs above 40 ug/100g, your risk of disease increases.
  • The blood lead levels of workers who intend to have children should be maintained below 30 ug/100g to minimize adverse reproductive health effects to the parents and to the developing fetus.

7. The best way to prevent all forms of lead-related impairments and diseases is to maintain lead levels in the blood below _____ of lead per 100 grams of blood.

a. 30 micrograms
b. 40 micrograms
c. 50 micrograms
d. 60 micrograms

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A cranes outrigging supported in muddy conditions.
Lead can affect the entire family.

Reproductive Risks

Lead is toxic to both male and female reproductive systems. Lead can alter the structure of sperm cells and there is evidence of miscarriage and stillbirth in women exposed to lead or whose partners have been exposed. Children born to parents who were exposed to excess lead levels are more likely to have:

  • have birth defects,
  • have an intellectual disability (mental retardation),
  • have behavioral disorders, or
  • die during the first year of childhood.

Workers who desire medical advice about reproductive issues related to lead should contact qualified medical personnel to arrange for a job evaluation and medical follow-up —particularly if they are pregnant or actively seeking to have a child. Employers whose employees may be exposed to lead and who have been contacted by employees with concerns about reproductive issues must make medical examinations and consultations available.

Chelating Agents

Under certain limited circumstances, a physician may prescribe special drugs called chelating agents to reduce the amount of lead absorbed in body tissues.

  • Using chelation to lower BLLs but while workers continue to be exposed is prohibited.
  • Therapeutic or diagnostic chelation of lead must be done under the supervision of a licensed physician in a clinical setting.
  • The employee must be notified in writing before treatment of potential consequences and allowed to obtain a second opinion.

Click on the button below to learn about preventive measures.

8. What action must the employer take if an employee who may be exposed to lead expresses concerns about reproductive issues?

a. Place the employee on extended paid leave of absence
b. Make medical exams and consultations available to the employee
c. Reassign the employee to another position in the company
d. Make sure the employee agrees to sign a medical release form

Check your Work

Read the material in each section to find the correct answer to each quiz question. After answering all the questions, click on the "Check Quiz Answers" button to grade your quiz and see your score. You will receive a message if you forgot to answer one of the questions. After clicking the button, the questions you missed will be listed below. You can correct any missed questions and check your answers again.

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