How Products were Selected:Products tested represent those commonly sold and/or available in the U.S. ConsumerLab.com purchased products on the open market through retail stores, on-line retailers and direct sales companies. Products were not accepted directly from manufacturers.
Testing Methods:Products containing alginic acid or sodium alginate were tested in one or more independent laboratories for the following:
- Identification assay by precipitation for sodium alginate or alginic acid (NF 31, modified).
- Quantitative analysis of lead, cadmium, arsenic and mercury by ICP-MS.
ConsumerLab.com may modify or use other appropriate test methods if necessary to test special product formulations.
Identities of the products were not disclosed to the laboratories performing the testing.
Passing Score:*To achieve a "Pass" in the testing, a product had to:
- Form a gelatinous precipitate after being dissolved in water or sodium hydroxide and added to a solution of calcium chloride or sulfuric acid (NF 31 modified).
Heavy Metals: Products must not exceed the following limits:
- Products marketed for use by children may not exceed California's Prop 65 limits for lead in dietary supplements of 0.5 mcg per recommended daily serving with an additional allowance of 0.8 mcg if the product contains more than 1,000 mg/day of calcium.
- Products with a single serving weights of less than 5 grams which are not marketed for use by children, may not exceed California's Prop 65 limits for lead in dietary supplements of 0.5 mcg per recommended daily serving with an additional allowance of 0.4 mcg if containing 250-999 mg/day of elemental calcium, magnesium and potassium, 0.8 mcg if containing 1,000 mg/day of any combination of these minerals. An additional 0.5 mcg is provided if containing 250-999 mg/day of whole herb (not extract) ingredient or 1.0 mcg if containing 1000 mg/day or more of whole herb (not extract). However, total lead allowance will not exceed 2 mcg per recommended daily serving.
- Products with single serving weights of 5 grams or more which are not marketed for children may not exceed 2.5 mcg per serving nor 4.0 mcg per daily serving.
- If marketed for use by children, may not exceed 3.0 micrograms of cadmium per recommended daily serving (based on Canada's limit for a child weighing 75 lbs.). If not marketed for use by children, may not exceed 4.1 micrograms of cadmium per recommended daily serving (above which California's Prop 65 law requires a "reproductive harm" warning due to developmental toxicity and male reproductive harm).
- Contain less than 10 micrograms of total arsenic (EPA limit and state of New Jersey limits - based on 1 liter of water) and no more than 2.1 micrograms of inorganic arsenic per daily serving (Canada's limit in natural health products).
- May not exceed 2 micrograms of mercury per daily serving (based on EPA limit for mercury in 1 liter of water).
- Meet FDA labeling requirements.
* Passing scores allow for specific margins of technical error associated with each analysis. ConsumerLab.com reserves the right to disqualify a product at any time from passing its testing if it considers such product to present a safety risk or to provide misleading or inaccurate information in its labeling.