Transparency
Heavy Metals Testing
Our published test of Essential Mint lot 001 measured lead at 0.024 parts per million, about one forty-second of Washington State's 1 ppm limit for cosmetics. Arsenic and cadmium were not detected, and mercury was below the amount the lab could quantify. Read the lot 001 certificate for the measured values and detection limits.4
What we found
We sent a sample of our first production batch to an independent lab and had it tested for the four metals regulators care most about. Arsenic and cadmium were not detected. Mercury was below the lab's quantification limit, so the report does not give a reliable amount. Lead measured 0.024 parts per million. See the lot 001 certificate for the result and limits.
The analysis used a method also applied to pharmaceutical products. We publish the elemental certificate and microbiology report with the labs' qualifications intact.2
"Not detected" does not mean zero
Every instrument has a floor it cannot see beneath. Ours could pick things up down to about 3 parts per billion for some analytes. Below a detection limit, the lab cannot tell from that test whether a substance is absent or present at a lower level. The exact limit varies by analyte in the report.
This is why detection limits matter more than the headline. A test that reports "none found" with a high floor tells you far less than a test that finds a small number with a very low one. We are not claiming a lead-free toothpaste. Lead was found in our product and we are printing the number.
What that number means
A number on its own is not information. Washington State caps lead in cosmetics at 1 part per million. We manufacture in Seattle, so that is the rule that binds us, and our result is about one forty-second of it.4
Dose is more useful than concentration. Brushing twice a day with a pea-sized amount puts about 0.012 micrograms of lead in your mouth per day, and that assumes you swallow every bit of it rather than spitting it out. For context, California's Proposition 65 uses a 0.5-microgram-per-day threshold for lead exposure that triggers reproductive-toxicity warnings; that threshold is not a declaration that lower exposure is safe.67
Why there is any lead in toothpaste at all
Lead, arsenic, cadmium and mercury occur naturally in the ground. Mineral ingredients such as chalk, clays, silicas and hydroxyapatite can carry traces into finished products. An ingredient name alone cannot establish the amount in a particular toothpaste; that requires measurement.
Words such as "natural" and "clean" do not tell you the elemental result. A finished-product report should identify the tested sample and show the measured value and detection limit.
What this page does and does not claim
- These figures describe the submitted sample from lot 001. They do not establish results for other or future lots.
- It is not a health claim. Nothing here says our toothpaste prevents or treats anything.
- It is not a comparison to any named brand. Different labs, methods and detection floors do not line up against each other, and we have not tested competitor products ourselves.
- No level of lead exposure is known to be free of harmful effects. The goal is not to sit comfortably under a limit, it is to keep pushing the number down.
Read the full lab report The full elemental panel, both certificates unedited, and how to read a limit of detection.
This page publishes the elemental panel for one submitted sample of Essential Mint lot 001, the certificate of analysis behind it, and the limits of what that result can establish. For context, a separate 2025 chart found lead in 46 of 51 toothpaste products selected for testing. That sample is not a market-wide prevalence estimate.1
The results
One retained sample of Essential Mint from lot 001 was submitted to an independent analytical laboratory and tested for the four elements that regulators treat as the priority set: arsenic, cadmium, mercury and lead. The analysis ran under USP General Chapter <233>, the inductively coupled plasma spectrometry procedure used to release pharmaceutical products.2
| Element | Result | Limit of detection | Limit of quantification | Report limit | Status |
|---|---|---|---|---|---|
| Arsenic (As) | Not detected | 0.002935 ppm | 0.008633 ppm | < 3 ppm | Within specification |
| Cadmium (Cd) | Not detected | 0.002935 ppm | 0.008633 ppm | < 5 ppm | Within specification |
| Mercury (Hg) | Below quantification | 0.002935 ppm | 0.008633 ppm | < 1 ppm | Within specification |
| Lead (Pb) | 0.02377 ppm | 0.002935 ppm | 0.008633 ppm | < 1 ppm | Within specification |
We are publishing the certificate unedited, including the laboratory's own qualifiers. The report carries the standard notes that product details are supplied by the client and are not verified by the laboratory, and that not all of the laboratory's methods hold ISO/IEC 17025:2017 accreditation. We would rather you read those lines than have us paraphrase them away.
How to read a result of "not detected"
"Not detected" is not the same claim as "zero." Every instrument has a floor. Two numbers define it, and both appear on the certificate:
- Limit of detection (LOD), 0.002935 ppm. The smallest amount the instrument can reliably distinguish from background noise. Below this, the laboratory cannot say anything is there.
- Limit of quantification (LOQ), 0.008633 ppm. The smallest amount the instrument can put an accurate number on. Between the LOD and the LOQ, a laboratory can tell that something is present but cannot say precisely how much.
So the honest reading of this panel is: arsenic and cadmium were not present above roughly three parts per billion. Mercury was detected somewhere below nine parts per billion, too little to quantify. Lead was present and measurable, at 0.02377 ppm, which is about 24 parts per billion.
We are not claiming a lead-free toothpaste. Lead was detected in our product, and we are printing the number rather than hiding behind a "not detected" from a laboratory with a higher floor. A test that reports "none found" at a detection limit of 0.5 ppm tells you far less than a test that finds 0.024 ppm at a detection limit of 0.003 ppm. Detection limits are the part of a lab report that marketing tends to leave out.
Putting 0.024 ppm of lead in context
A number in isolation is not information. Here is how 0.02377 ppm sits against the standards that actually apply to a product like this one, and against the exposure thresholds toxicologists use.
Washington State: 1 ppm
A toothpaste that contains no fluoride and makes no therapeutic claims is regulated in the United States as a cosmetic rather than as an over-the-counter drug.3 Washington's Toxic-Free Cosmetics Act set the first state lead standard in the country: as of January 1, 2025, cosmetic products sold in Washington may not contain lead at or above 1 ppm.4 We manufacture in Seattle, so this is the binding rule for us. Our result is roughly one forty-second of that limit.
FDA guidance for cosmetics: 10 ppm
The FDA recommends a maximum of 10 ppm lead as an impurity in cosmetic lip products and externally applied cosmetics, a level the agency concluded would not pose a health risk and which more than 99 percent of the 685 products it surveyed already met.5 That guidance was not written with toothpaste in mind, so treat it as a reference point rather than a rule we are held to. Our result is roughly one four-hundredth of it.
Daily exposure: Proposition 65 and USP
Concentration matters less than dose. A pea-sized amount of toothpaste is about 0.25 g,6 so twice-daily brushing puts roughly 0.5 g of paste in the mouth per day. At 0.02377 ppm, that whole 0.5 g carries about 0.012 micrograms of lead.
California's Proposition 65 sets the maximum allowable dose level for lead, as a reproductive toxicant, at 0.5 micrograms per day.7 USP General Chapter <232> sets a permitted daily exposure for lead in orally administered drug products of 5 micrograms per day.8 The 0.012 microgram figure above is roughly 2.4 percent of the Proposition 65 level and roughly 0.24 percent of the USP level, and it assumes every last milligram of paste is swallowed rather than spat out.
That arithmetic is offered so you can check our work, not as a safety determination. It uses a single lot, a stated brushing quantity, and thresholds built for other product categories. Public health bodies including the WHO hold that no level of lead exposure is known to be without harmful effects,9 and we agree with the implication: the goal is not to sit comfortably under a limit, it is to keep pushing the number down.
Why there is any lead in toothpaste at all
Lead, arsenic, cadmium and mercury occur naturally in the earth's crust and can enter finished products through mineral raw materials. Examples used in oral care include calcium carbonate, hydroxyapatite, bentonite and other clays, and various silicas and salts. The ingredient list does not reveal the elemental concentration in a finished product.
This is why "natural" and "clean" claims on a carton tell you nothing about elemental purity. A finished-product result needs to identify the tested sample, method, measured value and detection limit.
A result from one submitted sample cannot establish a fixed number for the brand. Raw materials and manufacturing conditions can change, so this certificate should be read as a snapshot of lot 001.
The other panel: water activity and microbiology
Elemental purity is one half of a contamination question. The other half is microbiological, and it is the reason most toothpastes carry a preservative system. Essential Mint is anhydrous, an oil-based paste with no added water, so we also had the same lot tested for water activity and microbial load.
| Test | Result |
|---|---|
| Water activity (aw) | 0.352 |
| Aerobic plate count | < 10 CFU/g |
| Yeast and mold | < 10 CFU/g |
| Enterobacteriaceae | < 10 CFU/g |
Water activity is the measure that governs whether microorganisms can grow in a formulation at all. It is not the same as water content: it describes how much of the water present is free and available. USP General Chapter <1112> summarizes the thresholds. Gram-negative bacteria stop proliferating below about 0.91, gram-positive bacteria below about 0.86, most fungi below about 0.77, and even the most osmotolerant yeasts and xerophilic molds cannot grow below roughly 0.60.10
The tested sample's water activity of 0.352 was well below those growth thresholds. That result supports the formulation's approach to microbial control without an added preservative. It does not establish sterility, long-term stability or the result for every future sample.
What this page does and does not claim
- These are lot 001 results. They describe one submitted sample from that lot. No single certificate can speak for every tube or future production lot.
- It is not a health claim. Nothing here says that our toothpaste prevents, treats or reduces any disease or condition, or that lower elemental impurities produce a clinical benefit for you.
- It is not a comparison to any named competitor. The independent 2025 testing we reference is a third party's work with its own methods and detection limits. Results from different laboratories, methods and detection floors are not directly comparable, and we have not run competitor products ourselves.
- Detection limits bound the negatives. "Not detected" means below roughly 0.003 ppm on this method. It does not mean absolutely absent.
If you want to check any of this, the certificates are linked above in full and the standards we cite are all public. If you find an error on this page, write to support@athenanaturals.us and we will correct it.
References
- Lead Safe Mama LLC. Toothpaste chart data, April 2025 update, independent third-party laboratory testing of 51 toothpaste and tooth-powder products. tamararubin.com. Summarized in Gizmodo, April 18, 2025.
- United States Pharmacopeia. General Chapter <233>: Elemental Impurities, Procedures. usp.org.
- US Food and Drug Administration. Anticaries Drug Products for Over-the-Counter Human Use, 21 CFR Part 355. Fluoride toothpastes are regulated as OTC drugs under this monograph; non-fluoride dentifrices making no therapeutic claim fall under cosmetics regulation. ecfr.gov.
- Washington State Legislature. Toxic-Free Cosmetics Act, HB 1047 (2023), effective January 1, 2025. Prohibits cosmetic products containing lead or lead compounds at 1 ppm or above. Washington State Department of Ecology.
- US Food and Drug Administration. Lead in Cosmetic Lip Products and Externally Applied Cosmetics: Recommended Maximum Level, Guidance for Industry. fda.gov.
- Cochran JA, Ketley CE, Duckworth RM, et al. How much is a "pea-sized amount"? A study of dentifrice dosing by parents in three countries. International Dental Journal, 2013. PMID 24283281.
- California Office of Environmental Health Hazard Assessment. Proposition 65 No Significant Risk Levels and Maximum Allowable Dose Levels. Lead MADL, reproductive toxicity: 0.5 µg/day. oehha.ca.gov.
- United States Pharmacopeia. General Chapter <232>: Elemental Impurities, Limits. Oral permitted daily exposure for lead: 5 µg/day. usp.org.
- World Health Organization. Lead poisoning and health, fact sheet. who.int.
- United States Pharmacopeia. General Chapter <1112>: Application of Water Activity Determination to Nonsterile Pharmaceutical Products. usp.org.
Keep reading
Essential Mint
Seven ingredients, fluoride-free, no water, no preservatives, no surfactants. Made in small batches in Seattle.