Diamond Crystal Kosher Salt (3 lb box)

1. Ingredients 25% of the rating 5 of 5

   Salt only, per the USDA food record for an earlier 3 lb box and the maker’s “additive free” claim, with no anti-caking agent or added iodine.

2. Independent testing 35% of the rating 4 of 5

   No lead, cadmium or mercury at two independent labs. Each tested one sample, the Lead Safe Mama carton was foodservice stock, and microplastics were not conclusively identified.

3. Packaging 10% of the rating 4 of 5

   A paperboard box with a side pour spout. The maker does not say whether the box has a liner.

4. Trust 15% of the rating 4 of 5

   No recalls, Prop 65 notices or FDA actions found for the salt. Recalls under the name Diamond Crystal Brands, 2017 to 2019, cover cocoa, sauces and dessert mixes.

5. Value 15% of the rating 5 of 5

   About $4 a pound for one box ($3.66 at Amazon) and $2.85 by the case, about a third of the price of the other clean salts here.

The rating, 4.4 of 5, is the weighted average of these scores. See how we rank salt & minerals and our standard.

• WebstaurantStore (opens in a new tab) approx. $11.99 for one 3 lb box; $76.99 for a case of 9 ($8.55 a box). A restaurant supplier. In stock on 2026-10-23; the page says packaging may vary.
• Amazon (opens in a new tab) approx. $11 for a 3 lb box ($10.99, about $3.66 a pound). Sold and shipped by Whole Foods Market through Amazon. The listing says “New Packaging”; its barcode (013600000127) differs from the USDA record’s.

Prices as we saw them on October 23, 2026. They change often. These links carry no tracking code and earn us nothing.

1. Salt

• Independent Lead Safe Mama, tested at Purity Laboratories (the site earns affiliate income; this test came from its own funds, not a donor campaign) April 2025

  Tested Diamond Crystal Pure and Natural Kosher Salt, a 3 lb carton marked foodservice (lot 2025-071), by ICP-MS on 17 April 2025: lead below 5 ppb, cadmium below 5 ppb, mercury below 5 ppb, arsenic below 10 ppb. One sample. Open ↗ (opens in a new tab)

• Independent Mamavation (EPA-certified lab, not named; the site earns affiliate income) May 2026

  Tested Diamond Crystal Kosher Salt: aluminum, arsenic, mercury and lead not detected, cadmium below its reporting limit. It sits in the lowest-metals group, where lead was 45 ppb or less. Microplastics were not conclusively identified in any salt. One sample per brand. Open ↗ (opens in a new tab)

Is it free of lead and other heavy metals?

In the two independent tests, yes. Lead Safe Mama (opens in a new tab) found less than 5 ppb of lead, and Mamavation (opens in a new tab) found none, in a study where lead turned up in 96% of the first 23 salts. One sample each, so a later lot could differ.

Does it have anti-caking agents or other additives?

Not the kosher salt. The USDA record (opens in a new tab) for the 3 lb box lists salt only. Check the label on any other Diamond Crystal product.

Does it contain microplastics?

Unknown. No brand-level count is published, and Mamavation’s imaging could not conclusively identify plastic in any salt it tested. A 2018 study of 39 salt brands (opens in a new tab) found the most plastic in sea salt, but we do not know where Diamond Crystal’s salt comes from.

Is the foodservice box the same as the one in stores?

We could not confirm it. The carton Lead Safe Mama tested says foodservice, not for retail sale. The maker says it now offers the same kosher salt “in a refreshed brand and new size made for home chefs” (1 lb, 26 oz and 3 lb boxes), and sellers list both boxes under one name, but no lab has tested the new box.

Has the maker had Prop 65 notices or recalls?

None for the salt. The state’s Prop 65 search shows no notice for Diamond Crystal, ClassAction.org shows no suit, and the FDA’s recalls under Diamond Crystal Brands concern other foods. WebstaurantStore’s page carries a California Prop 65 banner that names no chemical.

• One ingredient. The USDA’s branded food record for an earlier 3 lb box lists salt and nothing else, a restaurant supplier calls it a pure kosher salt with no additives, and the maker calls it additive free.
• Two independent labs found no lead. In April 2025 Lead Safe Mama’s lab (Purity Laboratories) reported lead, cadmium and mercury below 5 ppb and arsenic below 10 ppb. Mamavation’s lab found aluminum, arsenic, mercury and lead not detected and cadmium below its reporting limit, which put it in its lowest-metals group.
• It is the cheapest salt here by far. $11.99 for the 3 lb box is about $4 a pound, and $2.85 a pound by the case. Lead Safe Mama tested it while looking for a clean salt that cost less than the two it had already cleared, Jacobsen’s and Maldon’s.

• The carton Lead Safe Mama tested (lot 2025-071) is marked “Foodservice Packaging, Not for Retail Sale.” The maker says it now sells the same kosher salt in a refreshed brand and size for home chefs, but we could not confirm the retail box comes from the same plant or lot.
• The maker’s pages (diamondcrystal.com, a Cargill brand) say the salt is additive free and made in the facilities used since 1886, but give no heavy metal results, no ingredient panel and nothing on what lines the box. The USDA record we cite is for an earlier box (barcode 013600020019, updated 2023); the new box on Amazon has barcode 013600000127.
• Each lab tested one sample, and no one has published a microplastics count for it. Mamavation’s imaging could not conclusively identify plastic in any salt it tested.
• It is not iodized: the carton says it does not supply iodide. If salt is a main source of iodine for you, see our iodine guide.
• Other Diamond Crystal salts do add things. The USDA lists tricalcium phosphate in its Salt Sense, and an anti-caking agent and dextrose in its iodized salt. Buy the plain kosher box.

1. Diamond Crystal Salt Co.: Kosher Salt Flakes product page. Maker’s page. Says it is the original no-additive kosher salt, now in a refreshed brand and new size for home chefs: 1 lb, 26 oz and 3 lb boxes. Opened in a browser; a plain download is refused. Open ↗ (opens in a new tab)
2. Diamond Crystal Salt Co.: About us. Maker’s page. Made in the same facilities since 1886, additive free, no mechanical compaction, 53% less sodium by volume than table salt. A Cargill brand. Open ↗ (opens in a new tab)
3. WebstaurantStore: Diamond Crystal Kosher Salt 3 lb, 9 per case. Independent source. $76.99 a case ($8.55 a box), $11.99 a box, 23 Oct 2026; describes the box, process and “no additives”. Open ↗ (opens in a new tab)
4. Amazon: Diamond Crystal Kosher Salt, 3 lb (new packaging). Independent source. $10.99 on 2026-10-23, sold by Whole Foods Market; item number 013600000127. Open ↗ (opens in a new tab)
5. USDA FoodData Central: Diamond Crystal Kosher Salt, 48 oz. Certifier or regulator listing. Cargill Salt Business Unit record, ingredients “salt”, barcode 013600020019, updated May 2023. It predates the new box. Open ↗ (opens in a new tab)
6. Lead Safe Mama: Testing Diamond Crystal Pure and Natural Kosher Salt (Oct 2025). Test report. Purity Laboratories report, case 2504268. The site earns affiliate income. Open ↗ (opens in a new tab)
7. Mamavation: Sea salt and Himalayan salt tested for heavy metals and microplastics. Test report. EPA-certified lab, one sample per brand. The site earns affiliate income. Open ↗ (opens in a new tab)
8. FDA enforcement reports: recalling firm Diamond Crystal. Certifier or regulator listing. Searched 23 Oct 2026. Recalls are under Diamond Crystal Brands for cocoa, sauces and dessert mixes; none is for the salt. Open ↗ (opens in a new tab)
9. California Attorney General: Prop 65 60-day notice search. Certifier or regulator listing. Searched by alleged violator on 23 Oct 2026: no notice for Diamond Crystal. Open ↗ (opens in a new tab)
10. Kim et al. (2018), Environmental Science & Technology: microplastics in food-grade salts (PMID 30285421). Independent source. 39 brands; 0 to 1,674 particles per kg in sea salts, 0 to 148 in rock salt, 28 to 462 in lake salt. Open ↗ (opens in a new tab)

• Jacobsen Salt Co. Pure Kosher Sea Salt Clean in three independent tests across two years, from Oregon seawater, but about $13 a pound and out of stock at the maker on 23 Oct 2026.
• Maldon Sea Salt Flakes A finishing salt with clean lead results in two independent tests, at about $13 a pound.

• Minerals, Sodium, and What to Look For Article How sea salt differs from refined table salt, why iodine still matters, what the actual sodium-and-health evidence says, and how to choose a salt that supports rather than undermines your diet
• Thyroid Essential Article Why iodine deficiency is still widespread, how the thyroid depends on it, and practical ways to optimize intake
• Reducing Your Microplastic Exposure Article Practical steps to minimize microplastic intake from water, food, and everyday products