E339 · Sodium phosphates

What is E339?

Sodium phosphates are sodium salts of phosphoric acid used in food as emulsifiers, stabilizers, and pH regulators (buffers). They are common in processed cheese, baked goods, and cured meats, where they help maintain texture and consistency. They also have non-food uses such as in detergents and water treatment, but the food-grade forms are regulated separately and considered safe at typical use levels.

Also appears on labels as: Sodium phosphates, Sodium phosphate salts, Sodium dihydrogen phosphate, Disodium phosphate, Trisodium phosphate, Monosodium phosphate, Food grade sodium phosphates, INS 339, E339, E 339, E-339, E339(i).

What the evidence says

• Contributes to overall dietary phosphate intake; high total phosphate consumption (from all sources) has been linked to cardiovascular and kidney strain, particularly in people with existing kidney disease.
• Frequent consumption of highly processed foods containing added phosphates may make it harder to track total phosphorus intake, which matters for people on phosphate-restricted diets.

Research behind the verdict

1. Phosphate-based Additives in Processed Foods: Health Implications of Sodium Phosphates — Katherine L Tucker et al., American Journal of Clinical Nutrition (2025). A comprehensive 2025 study examining phosphate-based additives including sodium phosphate (E339) in the US food supply and their health implications. The research found that phosphate additives like E339 have more rapid and efficient absorption than naturally occurring dietary phosphate, contributing significantly to total phosphorus intake. While generally recognized as safe, the study raises concerns about excessive exposure through processed foods, particularly for individuals with chronic kidney disease. The research emphasizes the need for better labeling and monitoring of phosphate additive consumption.[safe_in_moderation]

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