Is Cerussite Toxic?
Cerussite, PbCO3, is 77.54% lead by mass. In Great Britain lead falls under the Control of Lead at Work Regulations 2002, not EH40. What they say. Not advice.
Cerussite is lead carbonate, PbCO3, and 77.54% lead by mass, worked. In Great Britain lead is governed by the Control of Lead at Work Regulations 2002, which define lead to include any compounds of lead; COSHH regulation 5 steps aside for them, and EH40 lists no lead limit. Their workplace air limit is 0.15 mg/m3 over 8 hours. This is not health advice.
In short
- What it is. The Handbook of Mineralogy cerussite sheet gives PbCO3, orthorhombic, hardness 3 to 3.5, very brittle, density 6.55, with habits that include granular and pulverulent. Worked on standard atomic weights, lead is 207.2 of a formula mass of 267.208: 77.54%. The sheet’s ideal column prints PbO 83.53%, which is the same figure expressed as oxide.
- Which law, by elimination. COSHH 2002, regulation 5 says COSHH regulations 6 to 13 apply except where and to the extent that the Control of Lead at Work Regulations 2002 apply. HSE EH40/2005 Workplace exposure limits says asbestos and lead are regulated separately, and a whole-text search finds the element named in 4 places, none of them a Table 1 entry. The lead question goes to CLAW 2002.
- The definition test. Control of Lead at Work Regulations 2002, regulation 2 defines lead in three parts: lead including any compounds of lead and lead as a constituent of any substance or material; which is liable to be inhaled, ingested or otherwise absorbed by persons; and, by regulation 2(2), exposure arising out of or in connection with work at the workplace. Cerussite meets the first part by its formula. The second and third are about circumstances, not minerals, and this page does not decide them.
- Documented failure: the solubility shortcut. The NatSCA leaflet on the care and conservation of geological specimens names cerussite among common toxic specimens and says galena is not toxic because it is insoluble. The definition in regulation 2 draws no line by solubility: it says any compounds of lead, and its only solubility wording belongs to the definition of a low solubility glaze. Cerussite at 77.54% lead and galena at 86.60% both meet its first part.
- Not advice. This page is not health, safety or legal advice. CLAW 2002 and COSHH govern work; a concern about exposure or symptoms belongs with a clinician, and workplace duties with HSE. The general site note is toxic minerals in a collection.
| Document | Provision | What it says, as printed | Figure as printed |
|---|---|---|---|
| Handbook cerussite sheet | Chemistry | Ideal PbCO3: PbO 83.53, CO2 16.47; Tsumeb analysis PbO 83.27. No hazard statement | 77.54% lead by mass (worked) |
| COSHH 2002 | Reg. 5(1)(a)(ii) | Regulations 6 to 13 apply “except— (a) where and to the extent that the following Regulations apply, namely— … the Control of Lead at Work Regulations 2002” | — |
| HSE EH40/2005 | Para. 52 | “Asbestos and lead are regulated separately” | No lead entry in Table 1 |
| CLAW 2002 | Reg. 2, “lead” | Lead “(including lead alkyls, lead alloys, any compounds of lead and lead as a constituent of any substance or material) which is liable to be inhaled, ingested or otherwise absorbed by persons” | — |
| CLAW 2002 | Reg. 2, occupational exposure limit | Lead other than lead alkyls, “a concentration of lead in the atmosphere”, assessed by the content of the element lead, 8-hour time-weighted average | 0.15 mg/m3 (lead alkyls 0.10 mg/m3) |
| CLAW 2002 | Reg. 2, “significant” | Air above half the occupational exposure limit; “a substantial risk of any employee ingesting lead”; or a risk of skin contact with lead alkyls or other substances containing lead absorbable through the skin | Half the limit |
| CLAW 2002 | Reg. 2, “action level” (blood-lead) | Woman of reproductive capacity; young person; any other employee | 25, 40, 50 μg/dl |
| CLAW 2002 | Reg. 2, “suspension level” | Blood-lead, same three groups; urinary lead, woman of reproductive capacity and any other employee | 30, 50, 60 μg/dl; 25 and 110 μg Pb/g creatinine |
| CLAW 2002 | Reg. 2(2) | Exposure means exposure “arising out of or in connection with work at the workplace” | — |
| NatSCA leaflet | Common toxic specimens | Names “some lead minerals (eg. cerrusite)”; “The lead mineral Galena is not toxic because it is insoluble.” | Conservation guidance, not law |
Is cerussite toxic? What it is made of, worked
Cerussite is lead carbonate, PbCO3, 77.54% lead by mass; its sheet records it as very brittle and includes pulverulent among its habits. Method: with Pb 207.2, C 12.011 and O 15.999, PbCO3 has a formula mass of 267.208, of which lead is 207.2. The Handbook of Mineralogy cerussite sheet prints the ideal composition as PbO 83.53 and CO2 16.47, which the same arithmetic reproduces, and a Tsumeb analysis with PbO 83.27, which works out at 77.30% lead. The species page, cerussite, has the identification; it is not repeated here.
What the sheet does not say. The Handbook is a descriptive reference, and a whole-sheet search of the cerussite text finds no use of the word toxic. It records habits that run from crystals to 0.6 m to granular, pulverulent, stalactitic and massive material, and a tenacity of very brittle. The page gives those facts as the sheet prints them and draws no exposure conclusion from them.
How HSE describes the routes. HSE’s page on when you are most at risk from lead says your body absorbs lead when you breathe in lead dust, fume or vapour, or swallow any lead. The processes it lists are industrial: paint removal, smelting, battery work, manufacturing lead compounds and pigments, among others. It does not mention minerals or collections.
Which UK law covers lead minerals? The definition test
The definition test: under the Control of Lead at Work Regulations 2002, “lead” has three parts, and cerussite’s formula settles only the first. Control of Lead at Work Regulations 2002, regulation 2 defines lead as lead (including lead alkyls, lead alloys, any compounds of lead and lead as a constituent of any substance or material) which is liable to be inhaled, ingested or otherwise absorbed by persons, except where it is given off from the exhaust system of a vehicle on a road. Regulation 2(2) adds that a reference to an employee being exposed to lead is to exposure arising out of or in connection with work at the workplace.
Applied, part by part. First, is it lead or a compound of lead? Cerussite is PbCO3, a compound of lead, 77.54% by mass. Second, is it liable to be inhaled, ingested or otherwise absorbed? That depends on what is being done with it, and the regulation does not answer it for a mineral, so neither does this page. Third, is the exposure in connection with work at a workplace? That is a fact about the setting, not the specimen.
Why not COSHH or EH40. COSHH 2002, regulation 5 sets out that COSHH regulations 6 to 13 apply except where and to the extent that the Control of Lead at Work Regulations 2002 apply. HSE EH40/2005 Workplace exposure limits says, at paragraph 52, that asbestos and lead are regulated separately, and refers readers to the HSE website. A whole-text search of EH40 finds the element lead in 4 places: the heading and text of paragraph 52, and a notice of approval that refers to the occupational exposure limit for lead in regulation 2(1) of the Control of Lead at Work Regulations 2002. None is a Table 1 entry; the two other matches are the verb. The arsenic page, is orpiment toxic, and the mercury page, is cinnabar toxic, quote EH40 entries; for lead there is none to quote.
What figures does the lead regulation set?
CLAW 2002 sets one air limit for lead other than lead alkyls, 0.15 mg/m3 over an 8-hour time-weighted average, assessed as the element lead. Regulation 2 also defines significant exposure as air above half that limit, a substantial risk of any employee ingesting lead, or a risk of skin contact with lead alkyls or other lead substances absorbable through the skin. HSE’s significant-exposure page sets out the same three circumstances.
The blood and urine levels. The regulation’s action levels are blood-lead concentrations of 25 μg/dl for a woman of reproductive capacity, 40 μg/dl for a young person and 50 μg/dl for any other employee; its suspension levels are 30, 50 and 60 μg/dl, or urinary lead of 25 and 110 μg Pb/g creatinine. The legislation.gov.uk web text renders the micro sign as a stray character, so the units were read from the as-made PDF, which prints the same figures.
What this page does not do with them. These are workplace thresholds for air, blood and urine. This page does not convert any of them into a weight of cerussite, a time, or a handling rule, because the regulation does not, and nothing here says what is or is not a safe amount. This page is not health, safety or legal advice. A question about exposure or symptoms belongs with a clinician.
Is cerussite more toxic than galena? The solubility shortcut
Documented failure: the solubility shortcut. Conservation guidance separates galena from cerussite by solubility; the lead regulation’s definition does not. The NatSCA leaflet on the care and conservation of geological specimens lists arsenic, antimony and some lead minerals, giving cerussite as its example under the spelling cerrusite, among common toxic specimens, and adds that the lead mineral galena is not toxic because it is insoluble. It gives handling and storage recommendations for the group, which this page does not reproduce.
What the regulation says instead. CLAW 2002’s definition covers any compounds of lead and lead as a constituent of any substance or material. The only solubility wording in regulation 2 is in the definition of a low solubility glaze, one that does not yield to dilute hydrochloric acid more than 5 per cent of its dry weight of a soluble lead compound. So PbS at 86.60% lead, PbSO4 at 68.33% and PbCO3 at 77.54% all meet its first part, compounds of lead; the other two parts turn on circumstances, not on the mineral. Galena is covered on is galena toxic and anglesite on anglesite; this page does not rank the three, because none of the sources fetched here does.
Where to go. HSE for workplace duties under CLAW 2002; a clinician for any question about exposure or symptoms. The general site note is toxic minerals in a collection. Other hazard questions are indexed at the collecting guides. Nothing on this site is offered for sale; the wanted list is the only commercial route.