How to read a sea moss lab report (and what to ask any brand)
A lab report can look like a wall of acronyms and "less than" signs. But once you know four ideas — the reporting limit, NATA accreditation, arsenic speciation, and batch versus point-in-time testing — you can read almost any food test and tell a genuine result from a decorative one. We'll teach each idea using our own published reports as worked examples, and the whole point is that you can then ask any sea moss brand for the same documents.
This is general information, not medical advice.
First principle: you should be able to see the whole report
Before any acronym, one habit. A trustworthy result is the full report from a named laboratory, not a cropped screenshot or a number typed onto a marketing page. A single figure with no lab, no method and no date is a claim, not evidence. Ours are republished in full (personal details redacted) at — that's the format to expect from anyone.
1. The reporting limit (LOR / LOD)
Every test has a floor below which the instrument can't reliably measure. That floor is the Limit of Reporting (LOR) — sometimes written as the limit of detection (LOD). When a result reads "< 0.010 mg/kg", it doesn't mean zero; it means below the level this method can report.
Worked example. Our finished-product report shows mercury < 0.010 mg/kg and inorganic arsenic < 0.020 mg/kg. Read that correctly: mercury wasn't detected down to 0.010 mg/kg, and inorganic arsenic wasn't detected down to 0.020 mg/kg. That's a genuinely reassuring result — but the number after the "less than" sign matters. A brand quoting "< 5 mg/kg" for something is telling you far less than one quoting "< 0.02 mg/kg", because the second test looked far deeper. Always check what the reporting limit actually is.
The same logic applies to our gluten result: Not Detected at a reporting limit of 5.0 mg/kg. "Not Detected" is only as meaningful as the limit beside it, so we print the limit.
2. NATA accreditation (and why the method's scope matters)
NATA — the National Association of Testing Authorities — is Australia's accreditation body for laboratories. A NATA-accredited lab has been independently audited as competent for specific tests. On a report you'll see a NATA number; ours name their accreditations openly — for example Agrifood Technology (NATA #2726), Mérieux NutriSciences (NATA #345), and the National Measurement Institute (ISO/IEC 17025, #198).
Here's the nuance most brands skip: accreditation is per method, not blanket. A lab can be NATA-accredited overall while a particular test sits outside its accredited scope. Honesty means disclosing that.
Worked example. Our gluten test uses an ELISA method that falls outside the lab's NATA scope, and our arsenic speciation method is likewise outside NATA scope — so we say so, both times, rather than letting the NATA logo imply more than it covers. When you read any report, look for whether the brand distinguishes accredited from non-accredited methods. Silence there is a small red flag.
3. Arsenic speciation: inorganic vs organic
This is the one that separates a serious seaweed report from a superficial one. Seaweed naturally takes up arsenic from seawater, but not all arsenic is equal:
- Inorganic arsenic is the form of health concern, and it's the one food regulators set limits on.
- Organic arsenic (compounds like arsenobetaine and arsenosugars) is far less of a concern.
A report that gives only "total arsenic" blends the two together and can make a product look worse — or hide a problem — because you can't see the split. Speciation is the lab step that separates them so you can read the number that actually matters.
Worked example. Our newer panel reports them separately: inorganic arsenic < 0.020 mg/kg and organic arsenic 0.18 mg/kg. Compare the inorganic figure to the benchmark that applies: the FSANZ Food Standards Code sets a maximum level of 1 mg/kg of inorganic arsenic for seaweed (on an 85% hydration basis). Our inorganic result sits well under that. Note also what we don't invent: for cadmium, lead and mercury there is no seaweed-specific maximum level in Schedule 19 of the Code, so we don't manufacture a benchmark to look good against — we just report the numbers (for instance cadmium 0.014 mg/kg). If a brand only ever shows "total arsenic", ask them to speciate it.
4. Batch testing vs a point-in-time test
A single test proves the tested batch was fine on the tested day. That's real, but it's not the same as an ongoing programme. Seaweed is a natural product, so values move between harvests — iodine especially. A 2024 study found total iodine across edible seaweeds ranged from about 52 to over 1,300 mg/kg dry weight, and a systematic review confirmed how much species and processing shift these numbers (Zhou et al., 2024; Blikra et al., 2022). One heroic certificate from years ago doesn't cover today's jar.
Worked example. Rather than lean on a single snapshot, we publish a microbiology shelf-life series — Day 30, 50 and 60 all clear, with Listeria and Salmonella Not Detected per 25 g at Day 60 — plus dated heavy-metal panels (a 2023 panel and a newer March 2026 panel) and iodine tested on the finished gel. Multiple dated reports beat one lonely certificate. When you assess any brand, look at how many reports there are and when they're from, not just whether one exists.
Put it together: your five questions for any brand
You can now walk up to any sea moss seller — including us — and ask:
- Can I see the full lab report, from a named lab? (Not a cropped number.)
- What's the reporting limit on the results that read "less than"? (Deeper limits mean more thorough tests.)
- Is the lab NATA-accredited, and are any methods outside that accredited scope? (Honest reports disclose this.)
- Is the arsenic speciated into inorganic and organic? (Total-only tells you less.)
- Are there multiple, dated reports — ideally a batch or shelf-life series — not just one point-in-time test?
If a brand can answer all five, you're in good hands. If they can't, that silence is your answer.
We've tried to make ours answerable. The species, the iodine per serve, the speciated arsenic and heavy metals, and the microbiology series are all published in full at , and the product behind them is our . Ask us the five questions — then go ask everyone else.
References
- Food Standards Australia New Zealand. Survey of iodine levels in seaweed and seaweed containing products.
- Food Standards Australia New Zealand. Iodine in food and iodine requirements.
- Zhou S, Zhang D, Kong Y, Zhang Q, Cui X. In Vivo Bioavailability and In Vitro Bioaccessibility of Iodine in Edible Seaweeds: Method Development and Health Implications. Environmental Science & Technology. 2024;58(51):22553–22562. doi:10.1021/acs.est.4c08990
- Blikra MJ, Henjum S, Aakre I, et al. Iodine from brown algae in human nutrition, with an emphasis on bioaccessibility, bioavailability, chemistry, and effects of processing: A systematic review. Comprehensive Reviews in Food Science and Food Safety. 2022;21(2):1517–1536. doi:10.1111/1541-4337.12918
- National Association of Testing Authorities, Australia (NATA). About accreditation.