Glaze material · Restricted — read before using
Lead compounds
Also sold as: lead bisilicate, lead carbonate, litharge, red lead, galena
Historically the great low-temperature flux: soft, brilliant glazes with a wide colour response.
In published recipes
Used in 47 of 10,859 glaze recipes (0.4%)
Typical amount when present
55% of the dry batch — half of recipes fall between 40% and 65.2%.
Fired surface of those recipes
Glossy 64% · Satin matte 14% · Matte 14% · Satin 7%
Most often mixed with
Materials that appear in the same recipes most often.
Chemistry
- Raw formula
- 2PbCO3·Pb(OH)2
- Molecular weight
- 775
- Fired formula
- PbO
- Equivalent weight
- 258
- lead carbonate (white lead); litharge PbO 223; red lead Pb3O4 684 → PbO, eq. wt. 228
From Linda Arbuckle's materials table. Mineral formulas are idealized; buy an analysis for the bag you have. Equivalent weight is the weight that supplies one molecule of the fired oxide — the number glaze calculation uses.
What potters should know
Toxic and cumulative by ingestion and inhalation, and it can leach from fired glazes in contact with acidic food. Lead frits are safer to handle than raw lead, but the finished glaze's safety depends on the whole recipe. Claybench lists lead for reference; it does not recommend it for functional ware.
Handling and safety
Contains lead compounds. Toxic via ingestion and inhalation; prohibited in food-contact glazes in many jurisdictions. FDA 21 CFR 109.16 leach testing required before use on functional ware.
Dry ceramic materials generate respirable silica dust. Use a NIOSH-approved N95 or P100 respirator and adequate ventilation when mixing dry, and wet-clean surfaces.
This information is provided for planning purposes and is derived from publicly available sources including OSHA regulations, NIOSH guidance, and manufacturer safety data sheets. It does not constitute professional safety advice. Consult your material suppliers' SDS documents and applicable local regulations for authoritative safety guidance.
Questions
- How much Lead compounds do potters use in a glaze?
- Across 47 published glaze recipes containing it, the typical amount is 55% of the dry batch, with half of recipes between 40% and 65.2%. Colorants and additives sit far lower than fluxes and glass formers; treat these as a range to test around, not a target.
- What cone is Lead compounds used at?
- It appears in recipes across the range; the most common cones among published recipes are cone 04, cone 06, cone 08. Where a material sits depends on the rest of the recipe more than on the material itself.
- Is Lead compounds safe to use?
- It carries a specific hazard flag: Contains lead compounds. Toxic via ingestion and inhalation; prohibited in food-contact glazes in many jurisdictions. FDA 21 CFR 109.16 leach testing required before use on functional ware. Read the supplier's SDS and follow local rules before using it, and never assume a glaze is food-safe without testing.
Related materials
| Glaze material | recipes | typical |
|---|---|---|
| Ferro frit 3134 | 1,907 | 20% |
Sources. Usage figures are computed by Claybench over 10,859 glaze recipes compiled from publicly shared community recipe collections (snapshot 2026-02-27) — counts only; no recipe is reproduced, and the figures describe that collection, not every recipe in existence. Material roles and notes are paraphrased from Linda Arbuckle's Ceramic Materials handout unless noted. Hazard notes summarise supplier SDS guidance; read the SDS for the product you buy.
Claybench tracks your glaze materials, not just recipes
Inventory, hazard flags, and per-piece material cost — the same reference behind this page, wired into your studio.