Testing for heavy metals in food
EDF’s detailed recommendations on testing for heavy metals in food and food ingredients
Due to extensive environmental contamination and the potential for additional contamination from processing, arsenic, cadmium, and lead can get into food. EDF recommends that companies systematically test their food products as well as potentially-contaminated ingredients. Companies should use FDA’s approved method for inductively coupled plasma mass spectrometry (ICP/MS). Expected cost as of December 2019 is between $50 and $100 per sample.
Our prioritized list of potentially contaminated ingredients includes:
- Root crops such as sweet potatoes, beets, white potatoes and carrots;
- Grapes, apples, peaches, and pears but not bananas or oranges;
- Squash, green beans, and peas;
- Spices; and
- Carrageenan and algae-derived products.
Companies should investigate possible sources of contamination where testing finds measureable levels, or, in cases where FDA has set a tolerance, at more than one-tenth of that level. Because we know there are normal variations in food, if your measurements indicate levels over one-tenth the tolerance, then there might be a quality issue you should consider addressing. For the latest FDA tolerances for heavy metals, visit FDA’s webpages for arsenic and lead. For other heavy metals, refer to FDA’s main webpage on metals.
FDA’s method to measure heavy metals in food products and ingredients
In 2014, FDA updated its Elemental Analysis Manual (EAM) for heavy metals by adding inductively coupled plasma-mass spectrometric (ICP-MS) analysis, known as EAM 4.7, which enabled heavy metals evaluation at lower levels than the agency’s previous methods. The limits of detection (LOD) and limits of quantification (LOQ) for Method EAM 4.7 are:
- Arsenic: LOD of 1.3 parts per billion (ppb) or µg/kg and LOQ of 11.6 ppb;
- Cadmium: LOD of 0.4 parts per billion (ppb) or µg/kg and LOQ of 3.7 ppb; and
- Lead: LOD of 1.2 parts per billion (ppb) or µg/kg and LOQ of 10.9 ppb.
We recommend against using any method that does not involve ICP-MS because the LODs and LOQs are too high and you will have false negatives.
Examples of laboratories marketing heavy metals testing
EDF has evaluated two commercial labs: Brooks Applied Labs in Seattle, WA and Eurofins Food Integrity and Innovation Lab in Madison, WI and is comfortable recommending both. Healthy Babies Bright Futures used Brooks Labs for its heavy metal and inorganic arsenic analysis of baby food report in 2019.
As a member of the Baby Food Council, EDF is sponsoring a proficiency testing program through Fapas to evaluate laboratories’ ability to measure arsenic, cadmium, and lead levels in pureed food at levels less than FDA’s LOQ. All laboratories that test foods for heavy metals are invited to participate in that program. The results will be available in June 2020. Based on those results, EDF may have additional labs it can recommend for heavy metal testing.