Regulated battery composition markingBattery composition marking
Battery chemical symbols Pb and Cd (Hg on legacy products)
Pb or Cd below the crossed-out battery bin identifies lead or cadmium above the applicable EU threshold. Hg may still be encountered on older products placed under previous rules.
Pb / Cd · Hg legacyEuropean Union / EEAthresholds and use depend on current battery law
At a glance
What this symbol means
The chemical abbreviation provides composition information when the applicable legal threshold is met. Under the current EU Batteries Regulation, the required heavy-metal abbreviations are Pb and Cd; Hg is retained in this guide only to identify older markings.
Regulation (EU) 2023/1542 requires Pb or Cd above the stated thresholds. Mercury markings belong to former battery-labelling rules and can still appear on legacy products.
Recognition
How to recognise it
- Look beneath the crossed-out wheeled bin for the chemical abbreviation.
- Pb means lead and Cd means cadmium. Hg can appear on legacy products governed by previous rules.
Typical applications
Where it commonly appears
- lead-acid batteries
- nickel-cadmium batteries
- legacy mercury-containing button cells or older packaging
Practical decision
How to sort or dispose of it
- Use the appropriate battery collection or authorised hazardous route.
- Tell the operator about leakage, damage or unusual battery type.
- Do not mix large industrial or vehicle batteries with small portable-battery containers unless accepted.
Before disposal or return
- Protect terminals.
- Keep damaged batteries isolated and stable.
- Do not open the casing.
Avoid contamination
Common mistakes
Reading Pb as a brand or model code.
Putting a marked battery in general waste.
Trying to drain or dismantle the battery.
Important limitation
What it does not mean
It is not a disposal-bin code, state-of-charge indicator or instruction to dismantle the battery.
Questions
Frequently asked questions
What does Pb mean?
Pb is the chemical symbol for lead.
What does Cd mean?
Cd is the chemical symbol for cadmium.
Why might Hg appear on an older battery?
Hg is the chemical symbol for mercury and may appear under legacy marking requirements.
Verification
Sources
Sources checked 15 August 2026
Continue identifying
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