Battery Assembly » Stacking

Manual stacking station
Manual stacking station

After curing, the plates are stacked either by hand or by machine so that positive and negative plates alternate with an insulating separator in between. The major source of lead exposure in the stacking process is from oxide from the plates which can become easily airborne.

Figure 1. Ventilated scrap barrel

Potential Sources of Exposure

Figure 2. Contaminated clothing
  • Exposure to lead dust may occur from improperly handling plates in unsealed envelopes.

  • Tamping plates in unventilated areas, such as the rack, creates a puff of dust.

  • Lead oxide that accumulates on equipment, racks, and floors may become airborne.

  • Clearing stacking equipment jam-ups.

  • Exposure to lead may increase when scrap plates are handled improperly, such as throwing in unventilated pail.

  • Leaning against equipment may increase clothing contamination.

  • Exposure to lead may increase from emptying clean-out trays improperly, by dumping in unventilated area.

  • Lead dust may escape from the stacking machine if the hinged panels are not closed.

Figure 3. Central vacuum drop station

Possible Engineering Controls

  • Use downdraft or slot ventilation at workstations.

  • Provide a grating or a perforated plate tamping stand.
  • Use a ventilated scrap barrel (Figure 1).

  • Use a central vacuum drop.
    • Consider adding duct cleanout openings so that large particles will drop out and not plug the lines.

  • Provide exhaust ventilated storage rack.
  • Place pallets of plates on a rotating base.

  • Use local exhaust ventilation with machines that use shuttles for moving plates.
    • These machines may have higher airborne levels due to abrasion of the plates.

  • Use a laminar flow (supplied-air) island over operators workstation.

  • Provide a plastic or glass, see-through plate between the stackers breathing zone and the plates. Enclose the process, if possible, to minimize the ventilation requirements.

  • Provide rubber mats or grated walking surfaces.

Figure 4. Hand stacking

Possible Work Practice Controls

  • Tamp, break, or separate plates only in ventilated work areas.

  • Handle groups of plates with the hands only rather than leaning them against the stomach, chest, or chin.

  • Wear an apron (Figure 2).

  • Maximize the distance between the operators breathing and the plates by not stacking assembled groups more than three high.

  • Place, do not throw, defective plates into scrap barrel.
  • Cover drums with a plastic bag before removing them from the area.

  • Keep access doors to ventilated enclosures close, except when access in needed.

  • Provide adequate PPE, a change of clothes, and shower rooms (see OSHA Lead Requirements for PPE, Housekeeping, and Hygiene Facilities).

  • Maintenance:
    • Ensure that local exhaust ventilation is working properly.

    • Prevent cross drafts.

  • Housekeeping:
    • Vacuum work station and adjacent areas to prevent accumulation of oxide dust.

    • Vacuum off each row of plates before using.

    • Use dust suppression techniques, such as keeping floors wet, using dust suppression compounds, or vacuuming.

    • Vacuum clean-out trays (Figure 3) or dump in ventilated areas; do not dump them into unventilated barrels.