Viviers et al. 2021 - South African cannabis product metals

Viviers et al. analyzed 310 cannabis-based products submitted to a South African private laboratory for Class 1 and Class 2 elemental impurities. The paper reports aggregate detection and source-limit failure counts by product category, rather than individual sample concentration values. Arsenic and mercury are not speciated, so this page records them as total arsenic (tAs) and total mercury (tHg).

Key numbers

All samples were analyzed as received and reported against USP 232 / ICH Q3D oral and inhalation residue limits. The paper reports limits in µg/g; these are source comparison limits, not HMTc thresholds.

Table A1 reports oral-limit failures across all 310 samples:

Table A2 applies inhalation limits only to extract, liquid, and plant material categories (n = 213):

Table A3 reports detectable residues across the full dataset:

Table A4 summarizes samples rather than analytes: oral comparison passed 262 and failed 48 of 310 samples; inhalation comparison passed 119 and failed 94 of 213 applicable samples; 273 of 310 samples had at least one detectable heavy-metal residue and 37 had no detectable residue in the tested panel.

Methods (brief)

The study grouped samples as edible, extract, infusion, liquid, other, plant material, or solid. Approximately 200 mg of each sample was digested in 10% HNO3 for 1 h at 100°C, diluted 35-fold to 7 mL, and analyzed with internal standards Y and In. Calibration used a blank, five-point calibration curve, and control standards every 10 duplicates and at the end of each sample set. Table A5 reports validation precision, bias/recovery, LOD, and linearity for the tested elements; for example Cd precision was 2.04 %RSD, Pb 6.31 %RSD, tAs 4.25 %RSD, and tHg 5.03 %RSD.

Implications

This source provides South Africa market context for cannabis-based product categories, especially aggregate detection and source-limit failure frequencies. It does not publish individual concentration rows, means, medians, or ranges, so downstream evidence extraction should not invent occurrence concentrations from the pass/fail tables. The inhalation-product subset is outside the current food and personal-care product taxonomy, while oral cannabis products can remain visible through broad herbal-botanical and dietary-supplement routing.

Wiki pages this source may touch

• supplements-botanicals-herbs
• dietary-supplements
• herbal-botanicals
• cadmium
• lead
• arsenic-total
• mercury-total
• cobalt
• vanadium
• nickel
• thallium
• gold
• palladium
• platinum
• silver

Verification notes

• Identity checks before writing found no existing DOI, raw-handle, or cite-key page for 10.1016/j.fsir.2021.100224, MFK_viviers2021, or viviers2021-south-africa-cannabis-metals.
• All Key numbers were rechecked against /tmp/hmi-june9-viviers2021.txt, extracted with pdftotext -layout, especially Tables 1, A1, A2, A3, A4, and A5.
• Speciation check: arsenic and mercury are not speciated; this page uses tAs and tHg and does not infer iAs or MeHg.
• Units are preserved as µg/g, ppm, %RSD, and the source’s sample counts. No unit conversions were performed.
• Brand firewall: the dataset is anonymized and no sampled brands are named.
• Missing slug note: the taxonomy snapshot has no cannabis-specific product, ingredient, vape, or inhalation-product slug. Frontmatter uses broad [[ingredients/herbal-botanicals]], [[products/supplements-botanicals-herbs]], and [[products/dietary-supplements]], while cannabis route/form terms are retained only as matrix descriptors.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.