Exposure to lead is the primary health concern in battery
manufacturing, and consequently, the focus of this topic page. Any operation in
which battery plates, lead scrap, or oxide is handled may be a significant
source of lead exposure. Airborne dispersion of lead dust
(which settles on equipment, floors and other surfaces) via cross-drafts,
pedestrian and vehicular traffic, and dry sweeping, may be an additional source
of lead exposure.
If the dross that forms on top of lead pots is handled carelessly, lead exposure
can result. Lead particles can also become airborne via attachment to acid or water mists. Lead fumes from lead pots, torching, burning, or other operations where a flame contacts lead, or lead is heated above the melting point, may also be sources of lead exposure.
This section highlights OSHA standards, preambles to final rules (background to final rules), directives (instructions for compliance officers), and standard interpretations (official letters of interpretation of the standards) related to battery manufacturing.
Note: Twenty-five states, Puerto Rico and the Virgin Islands have OSHA-approved State Plans and have adopted their own standards and enforcement policies. For the most part, these States adopt standards that are identical to Federal OSHA. However, some States have adopted different standards applicable to this topic or may have different enforcement policies.
Preambles to Final Rules
lead dust is the most significant health exposure in battery
manufacture. Lead can be absorbed into the body by inhalation and ingestion. Inhalation of airborne lead is generally the most important source of
occupational lead absorption. Once in the blood stream, lead is circulated
throughout the body and stored in various organs and body tissues (e.g., kidney
liver, brain, bone marrow, bones and teeth). Absorption via the gastrointestinal track
following ingestion is highly dependent upon the presence of levels of calcium,
iron, fats, and proteins.
Short term (acute) overexposure
Lead adversely affects numerous body systems, and causes forms of health impairment and disease which arise after periods of exposure as short as days or as long as several years. Lead is a potent, systemic poison, which when taken in large doses, can kill a person in a matter of days. A condition affecting the brain called acute encephalopathy may arise which develops quickly to seizures, coma, and eventually death from cardiorespiratory arrest. Short term occupational exposures of this magnitude are highly unusual, but not impossible. Similar forms of encephalopathy may also arise from extended, chronic exposure to low doses of lead. There is no sharp dividing line between rapidly developing acute effects of lead, and chronic effects which take longer to acquire.
Long term (chronic) overexposure
Chronic overexposure to lead may result in severe damage to the blood‑forming, nervous, urinary, and reproductive systems. Some common symptoms of chronic overexposure include loss of appetite, metallic taste in the mouth, anxiety, constipation, nausea, pallor, excessive tiredness, weakness, insomnia, headache, nervous irritability, muscle and joint pain or soreness, fine tremors, numbness, dizziness, hyperactivity and colic. In lead colic there may be severe abdominal pain.
Central Nervous System
Damage to the central nervous system and the brain (encephalopathy) is one of the more severe manifestations of lead poisoning. The most severe, often fatal, form of encephalopathy may be preceded by vomiting, 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. Some may experience muscular weakness as well. This weakness may progress to paralysis which is often observed as a characteristic "wrist drop" or "foot drop". It is a manifestation of a disease effecting the nervous system, called peripheral neuropathy.
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 A progression to kidney dialysis or death is possible.
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.
Additional chemical hazards in battery manufacturing include possible exposure to toxic metals, such as antimony (stibine), arsenic (arsine), cadmium, mercury, nickel, selenium, silver, and zinc, and reactive chemicals, such as sulfuric acid, solvents, acids, caustic chemicals, and electrolytes. For additional information, see OSHA's Safety and Health Topics Pages on:
Standard particulate sampling techniques are used to evaluate lead exposures. Potential for lead ingestion can be indicated by wipe sampling. Employers who are required to perform biological monitoring for blood lead must use an OSHA-approved blood lead laboratory for analysis.
Safety and Health Topics
Blood Lead Laboratories
Video Exposure Monitoring
Controlling the exposure to lead can be done through engineering controls, administrative actions, and personal protective equipment (PPE). Engineering controls include local exhaust ventilation, total enclosures where feasible, mechanical handling methods, and isolation of the source generating lead. Administrative actions include limiting the worker's exposure time, and requiring workers to shower and change into clean clothes before leaving the worksite. Personal protective equipment may include wearing the proper respiratory protection to keep workers' exposure below the OSHA permissible exposure limit and the use of personal protective clothing. The following references contain information to help reduce lead exposures.
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