Sodium Saccharin: A High-Intensity, Non-Nutritive Sweetener

CAS Registry Number: 128-44-9 (Anhydrous); 6155-57-3 (Dihydrate)

Overview

Sodium saccharin is the sodium salt form of saccharin, an artificial, non-nutritive sweetener. Its chemical formula is C₇H₄NNaO₃S, with a molecular weight of 205.17 g/mol . It appears as a white crystalline powder with an intensely sweet taste and is highly soluble in water, making it a versatile ingredient .

The anhydrous form (CAS 128-44-9) and the dihydrate form (CAS 6155-57-3) are the most commonly encountered commercial versions . The dihydrate form is often preferred for its enhanced handling and solubility in aqueous systems . Sodium saccharin is approved for use in more than 100 countries and carries the E number E954 .

Sweetness and Key Properties

• Sweetness Intensity: Approximately 300–500 times sweeter than sucrose (table sugar) .

• Stability: Highly heat-stable, making it suitable for cooking, baking, and use in processed foods . However, it can decompose at very high temperatures (e.g., complete decomposition at 190°C for 40 minutes during frying) .

• Solubility: The parent acid saccharin is only sparingly soluble, but the sodium and calcium salts are highly water-soluble (0.67 g/mL at room temperature) .

• Aftertaste: When used alone, sodium saccharin can have a slight bitter or metallic aftertaste. It is often blended with other sweeteners to achieve a more sugar-like flavor profile .

Major Applications

Food and Beverage Industry

Sodium saccharin is widely used as a calorie-free sugar substitute in a variety of applications:

• Beverages (e.g., soft drinks) 

• Tabletop sweeteners 

• Processed foods 

• Baked goods, confectionery, and canned goods 

Pharmaceuticals

It is commonly used in pharmaceutical formulations to mask the unpleasant taste of oral medications .

Other Uses

• Personal care products 

• Animal feed as a sensory/flavouring additive 

• Electroplating brightener formulations 

Safety Information

Regulatory Status and History

The safety of sodium saccharin has been extensively studied and debated. In the 1970s, studies linked high doses of sodium saccharin to bladder tumors in male rats, which led to warning labels and, in some countries, a moratorium on its use . This historical controversy has been largely resolved by subsequent scientific research.

Current Scientific Consensus

Modern regulatory bodies and scientific panels have concluded that the mechanism causing bladder tumors in male rats is species-specific and not relevant to humans. It occurs through a non-genotoxic, high-dose mechanism involving sodium ion-induced precipitation in the rat bladder, which is a phenomenon not applicable to humans . Key points from authoritative reviews include:

• No evidence of carcinogenicity in humans: Extensive epidemiological studies have not demonstrated an association between saccharin consumption and bladder cancer in human populations .

• No metabolism in the body: Saccharin is excreted unchanged in the urine, with no evidence of accumulation or metabolism in animals or humans .

• Not genotoxic: Tests do not support a mechanism involving direct interaction with DNA