Heavy-metal limits: UK rules and other benchmarks

The GB legal limits

“As sold” matters

The limits apply to the supplement as placed on the market. For shilajit resin, that means the resin as it is in the jar, including its moisture, not a dried or concentrated version. A report given on a dry-weight basis will show higher figures than the as-sold product; a report given per serving will show much smaller numbers. Check the basis before comparing with the limit; see units on lab reports.

Why arsenic is different

GB supplement maximums cover lead, cadmium and mercury.^[1] Total arsenic has no specific supplement maximum, partly because its toxicity depends on its chemical form: inorganic arsenic is generally considered the more harmful fraction. Read arsenic results with their uncertainty, convert them to a daily intake, and prefer products tested for inorganic arsenic; see arsenic in shilajit.

Converting a result to daily intake

Other benchmarks you may see

Some reports and brands refer to other benchmarks, such as daily-exposure limits used in pharmacopoeia standards, or limits from other countries. These use different methods, often expressing limits as micrograms per day rather than mg/kg. They can be useful context, but the GB legal limits are the ones that apply to products sold in Great Britain. If a report quotes another benchmark, check which one, and whether the product also meets GB limits.

Results close to a limit

A result just below a limit deserves attention, because measurement uncertainty means the true value could be slightly higher. A product that consistently sits well below the limits is a safer long-term choice. If successive batches from the same brand drift towards a limit, ask why; see variation between samples.

Reading a report against the limits

1. Find lead, cadmium and mercuryIn mg/kg.
2. Check the basisAs sold, not dry weight or per serving.
3. Compare with GB limits3.0, 1.0 and 0.1 mg/kg.
4. Note uncertainty and detection limitsSee detection limits.
5. Check arsenic separatelyWith its form and uncertainty.

A documented report to practise on

The AGROLAB LUFA report for Nature Elixirs batch SJ2509 gives results for lead, cadmium, mercury and total arsenic in mg/kg, along with other contaminants.^[2] It is a useful real document for practising these steps; the full report is linked from our Nature Elixirs evaluation. Nature Elixirs is a brand evaluated by Best Shilajit UK. Read our evaluation to see the evidence and documentation we reviewed.

Why the limits differ between metals

The three limits reflect how harmful each metal is at low exposure and how much people take in from other sources. Mercury’s limit is the strictest at 0.1 mg/kg, lead’s the most generous at 3.0 mg/kg, with cadmium in between at 1.0 mg/kg.^[1] A higher limit doesn’t mean a metal is harmless; lead in particular has no known safe level of exposure. The limits are legal ceilings, and the goal for any product should be to sit comfortably below them.

Consistency matters too

One compliant batch is good; a run of batches that all sit comfortably below the limits is better. Brands that publish reports for every batch let you see that consistency.

Who enforces the limits

In the UK, local authority enforcement officers check food law compliance, including contaminant limits.

In short

Compare mg/kg as sold with the GB limits, and prefer results well below them.

The bottom line

GB law caps lead, cadmium and mercury in supplements at 3.0, 1.0 and 0.1 mg/kg as sold, with no supplement maximum for total arsenic. Compare results on the right basis, convert to daily intake for perspective, and favour products that sit well below the limits batch after batch.

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