In brief
Lead enters the body mainly through inhaled dust and fumes, and also from contaminated hands to the mouth; this is why hand washing, eating arrangements and work clothing rules are as much a part of protection as ventilation. The Chemical Substances Regulation sets an occupational exposure limit value of 0.15 mg/m³ for inorganic lead and a binding biological limit value of 70 µg/100 ml in blood; medical surveillance is mandatory when 0.075 mg/m³ in air or 40 µg/100 ml in blood is exceeded. The workplace physician plans the timing of blood lead tests and the interpretation of results.
In which jobs does lead exposure occur?
Although its use has declined over the years, lead is not a metal that has disappeared from industry. In automotive supplier and metalworking facilities, battery service centres, electronics repair workshops and the maintenance of old metal structures in Bursa and neighbouring provinces, lead exposure is still a health risk that is encountered. The insidious side of the problem is that lead accumulates in the body and the symptoms appear only after a long time, in a vague form.
The main sources of exposure are:
| Job | Source of lead | Main route of entry |
|---|---|---|
| Battery manufacture and recycling | Grid casting, lead oxide paste, plate cutting, battery breaking | Inhaling dust and fumes, contaminated hands |
| Battery servicing and replacement | Oxide on terminals, broken casings | Contaminated hands, rarely dust |
| Electronics repair with lead solder | Solder wire and solder residues | Contaminated hands and hand-to-mouth contact |
| Removing old paint (metal structures, bridges, historic buildings) | Old paint layers containing lead | Dust and fumes from sanding, blasting and flame stripping |
| Lead casting and smelting | Molten metal surface | Inhaling fumes |
| Use of lead glazes and pigments | Glaze preparation, spraying | Inhaling dust |
Lead in battery work is where exposure is highest; especially in battery recycling, the breaking, separation and smelting stages produce heavy dust and fumes. Old paint removal, on the other hand, is a source that is usually overlooked: sanding the steelwork of a metal structure or the joinery of a historic building can lead to serious exposure even if lead is not used in the workplace. For other dusts in restoration work, see our article on OHS in historic building restorations.
How does lead enter the body?
Inorganic lead enters the body by two main routes:
- Inhalation: Fine dust and fumes produced during casting, smelting, cutting and blasting reach the lungs and are absorbed. The finer the particle, the deeper it goes.
- Ingestion: It is swallowed via hands contaminated with lead dust, cigarettes, food or cups. In many jobs, this route is at least as important as inhalation.
Absorption of inorganic lead through intact skin is limited; however, organic lead compounds such as tetraethyl and tetramethyl lead are also absorbed through the skin. This is why these compounds are marked "Skin" in Annex 1 of the Chemical Substances Regulation.
There is a common misunderstanding about solder fumes. At hand soldering temperatures, very little lead evaporates; the visible part of solder fumes that irritates the respiratory tract comes largely from the flux (rosin). For solderers, the main route for lead is hands that have touched solder wire and residues being brought to the mouth. Soldering benches therefore need both extraction at source for flux fumes and hand hygiene for lead. For how to check extraction, see our article on local exhaust ventilation.
Exposure also has an invisible end: lead dust carried home on work clothes, shoes and car seats. Children are far more sensitive to lead than adults; this is why the hygiene rules described below protect not only the employee but also their family.
Limit values and thresholds that make medical surveillance mandatory
The Regulation on Health and Safety Measures for Working with Chemical Substances is one of the rare pieces of legislation that sets limits for lead both in air and in blood:
| Value | Equivalent in the regulation |
|---|---|
| Occupational exposure limit value (Annex 1) | Inorganic lead and its compounds: 0.15 mg/m³ (8-hour time-weighted average) |
| Binding biological limit value (Annex 2) | 70 µg Pb/100 ml blood |
| Medical surveillance threshold: air (Annex 2) | If the time-weighted average calculated on a 40-hour working week exceeds 0.075 mg/m³ |
| Medical surveillance threshold: blood (Annex 2) | If lead in the blood of any employee exceeds 40 µg Pb/100 ml |
The practical meaning of this table is: lead in air is known through workplace atmosphere measurement, lead in blood through biological monitoring, and when either threshold is exceeded, medical surveillance is no longer optional. We plan workplace atmosphere measurements with accredited laboratories and enter the results into the risk assessment. We have gathered which measurements are needed in which workplaces in our article on workplaces requiring workplace atmosphere measurements.
Blood lead testing: the physician plans biological monitoring
Art. 12 of the regulation requires health surveillance in line with the procedure in Annex 2 for work with substances that have a biological limit value in that annex, and requires employees to be informed of this before starting work. Under Annex 2, biological monitoring covers the measurement of the blood lead level (PbB) by absorption spectrometry or a method giving equivalent results. The legislation does not tie the frequency of measurement to a fixed schedule; the workplace physician determines the timing according to the level of exposure and previous results. We plan the tests with authorised health institutions.
Well-planned biological monitoring includes the following steps:
- Baseline value at the start of employment: The value taken before starting work with lead is the reference against which later results are compared.
- Periodic measurement according to exposure: More frequent in intensive work such as battery recycling, less frequent in low-exposure work such as hand soldering; the physician sets the frequency.
- Correct sampling: Blood is taken from a cleaned area, to avoid contamination from soiled skin, and after work clothes have been removed.
- Interpretation of the result and feedback: The result is explained to the employee; for an employee showing an upward trend, their work, hygiene and PPE use are examined on site.
If the biological limit value is exceeded, Art. 12 sets out a clear path: the employee is informed, the risk assessment is reviewed and renewed if necessary, the measures are re-evaluated, the recommendations of the workplace physician and the OHS specialist, including transferring the employee to other work without exposure, are taken into account, and the health of other people doing the same work is also checked. Health and exposure records are kept; if the workplace ceases operations, these records are handed over to the SGK (Social Security Institution) provincial directorate. For the general framework of periodic examinations, see our article on periodic examinations and tests.
Symptoms of lead poisoning
Symptoms of lead poisoning begin with vague, non-specific complaints, which is why they are often attributed to other causes:
- Tiredness, weakness, headache, sleep and concentration problems
- Loss of appetite, constipation, cramp-like abdominal pain
- Joint and muscle pain
- Anaemia
- In advanced cases, weakness in the hands and feet, kidney involvement and high blood pressure
Lead also affects reproductive health. The safety data sheets of most lead compounds carry a reproductive toxicity warning. Annex I of the Regulation on the Working Conditions of Pregnant or Breastfeeding Women essentially prohibits pregnant and breastfeeding employees from working in jobs where chemicals toxic for reproduction are used. Plans should be made to remove an employee who reports a pregnancy from work involving lead exposure immediately; for details, see our article on pregnant and breastfeeding employees.
If symptoms and test results suggest an occupational disease, the process is the workplace physician's responsibility; see the physician's role when an occupational disease is suspected.
Personal hygiene measures: not carrying lead to the mouth or home
With lead, hygiene is not a complement to engineering controls but a layer of protection of equal importance. The measures can be listed as follows:
- No eating, drinking or smoking in the work area. Meals are eaten in a separate, clean area after washing hands and face. Cigarettes and phones are the objects most often brought to the mouth with dirty hands.
- A hand washing point at the exit of the work area. Nails are kept short; washing is done before meals, before smoking and at the end of the shift.
- Two-compartment lockers. Annex 1, item 51 of the Regulation on Health and Safety Measures in Workplace Buildings and Annexes requires two-compartment or two separate lockers where work involves dust, dirt or hazardous substances, so that work clothes and outdoor clothes can be stored separately; item 52 requires shower facilities where the work requires them.
- Work clothes do not go home. Work clothes contaminated with lead are laundered at the workplace; employees shower at the end of the shift and only then put on their own clothes.
- Wet cleaning. Benches and floors are cleaned with a wet method or a HEPA-filtered vacuum instead of dry sweeping or compressed air.
On the engineering side, the priority is to prevent lead from getting into the air: local exhaust at smelting and casting points, not keeping temperatures higher than necessary, and using chemical strippers or wet methods instead of flame burning and dry sanding on old paint. If these are not enough, suitable respiratory protection is used; for mask selection, see our article on dust masks FFP1, FFP2, FFP3.
We plan biological monitoring and periodic examinations for work involving lead as part of our health surveillance service; for other sector-specific risks, see our metal and machinery sector page.
Frequently Asked Questions
How often should blood lead testing be carried out?
The legislation does not set a fixed frequency. The workplace physician determines the timing according to the thresholds in Annex 2 of the Chemical Substances Regulation and the level of exposure. Taking a baseline value at the start of employment and measuring more frequently in high-exposure work is recommended.
What is the legal limit for lead in blood?
The binding biological limit value is 70 µg Pb/100 ml of blood. Medical surveillance is mandatory if 40 µg/100 ml is exceeded in the blood of any employee or if lead in air exceeds 0.075 mg/m³ as a weekly average.
Does an employee who solders inhale lead?
At hand soldering temperatures, very little lead evaporates; most of the visible fumes come from the flux. For solderers, the main route for lead is contaminated hands brought to the mouth. Extraction for flux fumes, hand hygiene for lead and a ban on eating and drinking in the work area are therefore applied together.
Is a service employee who replaces batteries also at risk?
Exposure is low compared with battery manufacture and recycling, but it is not zero. Oxide on terminals and broken casings carry lead through hand contact. Using gloves, washing hands at the end of work and not eating in the service area are the basic measures.
An exposure-based test plan, pre-employment and periodic examinations, confidential health files and an examination schedule tracked per person.
Bursa SİSTEMER OSGB Technical Team — written from the field experience of our OHS specialists and workplace physicians. Legal information is valid as of the publication/update date; contact us for an assessment specific to your business.