E954 – Saccharin - Food additives database

Safety Grading ORANGE – SOME CONCERNS

Regulators currently consider saccharin (E954) safe at permitted uses, but a few points justify caution. In November 2024, EFSA completed its re‑evaluation and set a new acceptable daily intake (ADI) of 9 mg/kg bw/day, replacing the earlier lower value and confirming overall safety at typical dietary exposure. EFSA also recommended revising EU specifications and keeping manufacturing restricted to the Remsen–Fahlberg process to control impurities. The FDA likewise permits saccharin use in foods and tabletop sweeteners.

Evidence sweep: Modern human data do not support a carcinogenic risk at realistic intakes. Rodent bladder tumor findings from the 1970s are now considered not relevant to humans based on species‑specific mechanisms. However, several recent studies explore potential metabolic or microbiome effects of intense sweeteners including saccharin. While results are mixed and often involve doses above typical intake, they motivate a conservative stance for heavy consumers and sensitive groups. Reviews and primary studies indexed on PubMed discuss gut microbiota shifts and glucose‑insulin dynamics in selected contexts – the overall evidence is inconsistent but worth monitoring.

Net‑risk judgment: Because E954 remains approved and exposure assessments indicate margins of safety at normal consumption, a RED grade would be inappropriate. Yet, lingering controversy around very high intakes, occasional digestive sensitivity, and precautionary specification updates make a blanket GREEN premature. Therefore, we assign ORANGE with clear usage guidance and caveats for frequent users and people with bladder irritation or GI sensitivity.

Should You Avoid Saccharin?

Most people do not need to avoid saccharin when intake stays well below the ADI. If you regularly consume multiple servings of diet beverages, sugar‑free syrups, or use large amounts of tabletop sweeteners, consider moderating or rotating with alternatives (e.g., stevia). Individuals with ongoing bladder irritation or a history of interstitial cystitis often report better comfort by minimizing saccharin. People managing gut dysbiosis or IBS may prefer to trial other sweeteners and monitor symptoms.

Common Uses

Diet soft drinks, flavored waters, and powdered drink mixes.
Tabletop sweeteners (sodium or calcium saccharin) for coffee and tea.
Sugar‑free jams, desserts, and chewing gum.
Toothpaste and certain pharmaceutical syrups for palatability.

Common Names / Synonyms

Benzoic sulfimide (saccharin).
Sodium saccharin, calcium saccharin, potassium saccharin.
E954, INS 954.

What Is It?

Saccharin is a non‑nutritive sweetener that is 300–500× sweeter than sucrose. Food‑grade saccharin is produced via the Remsen–Fahlberg route from o‑toluenesulfonamide (or related anthranilate chemistry), followed by cyclization to the benzoisothiazolinone‑1,1‑dioxide core and purification to food specifications. The final food forms are commonly the sodium or calcium salts, which are highly soluble and convenient for beverages and tabletop use. Saccharin is not metabolized for energy it is largely absorbed and excreted unchanged, which explains its zero‑calorie nature and minimal glycaemic impact. Technologically, it is prized for heat stability and synergy with other sweeteners, which allows manufacturers to reduce bitter notes and achieve sugar‑like profiles at low cost. Modern specifications also limit impurities (e.g., readily carbonisable substances) to ensure consistency and safety.

At realistic use levels, controlled human data have not demonstrated consistent adverse effects. However, dose makes the difference: extremely high intakes can lead to bitter/metallic aftertaste, occasional GI discomfort, and, rarely, idiosyncratic intolerance. As with any additive, context matters – overall diet quality, beverage acidity, and co‑ingested sweeteners can all modulate tolerance.

Where It’s Allowed (EU vs US)

Saccharin is authorised across the EU under Regulation (EC) No 1333/2008 and its implementing measures. EFSA’s 2024 opinion set an ADI of 9 mg/kg bw/day for saccharins. In the United States, saccharin is permitted by the FDA . The UK Food Standards Agency also lists E954 among approved sweeteners. Regional limits differ by food category, so manufacturers must follow national standards.

Historical Summary: Why E954 Was Banned for a Time

1. 1970s: Animal studies raise alarm

In 1972–1977, several long-term studies found bladder tumors in rats given very high doses of saccharin or sodium saccharin.
These effects occurred mainly when saccharin was combined with cyclamate (another sweetener banned in 1969).
Researchers noticed crystals forming in rat urine, which irritated the bladder lining – a mechanism later shown to be species-specific, not relevant to humans.
However, at the time this was interpreted as possible carcinogenicity.

2. 1977: FDA moves to ban saccharin

The U.S. Food and Drug Administration (FDA) invoked the Delaney Clause (which forbids any additive shown to cause cancer in animals).
In April 1977, the FDA proposed banning saccharin from food and beverages.
This triggered enormous public opposition – millions of consumers and diabetic patients protested, since saccharin was one of the few calorie-free sweeteners available.

3. 1977–1981: Congress imposes a moratorium

The U.S. Congress passed the Saccharin Study and Labeling Act (1977).
It allowed saccharin to remain on the market temporarily, but required warning labels: “Use of this product may be hazardous to your health. This product contains saccharin, which has been determined to cause cancer in laboratory animals.”
This warning stayed on all saccharin products until 2000.

4. 1990s–2000s: Re-evaluation and reinstatement

Later studies confirmed that the rat bladder tumors were due to a non-DNA-damaging mechanism (precipitation of calcium phosphate and saccharin crystals, not relevant to humans).
Health Canada (1997), U.S. National Toxicology Program (2000), and WHO/FAO JECFA (2003) removed saccharin from their lists of potential carcinogens.
The warning label requirement was dropped in the U.S. in 2000, and saccharin remained approved in both the EU and the U.S. under defined safe limits.

E954 – Saccharin