Total and unprotonated (freebase) nicotine content in new types of oral 'tobacco-free' nicotine products.

Significance: Nicotine-containing products, labelled as being 'tobacco-free' nicotine (TFN), are marketed to consumers as alternatives to conventional tobacco products. Little is known about these emerging products and their contents.

Methods: Moisture, total nicotine and pH content were analysed in 70 commercially available TFN products, covering five different types (lozenges, chewing gum, loose leaf, toothpicks and pouches). The freebase nicotine was calculated using the measured pH values.

Results: Total nicotine levels ranged from 0.822 to 31.5 mg/g. Nicotine levels were highest in nicotine pouches (1.41-8.11 mg/product) and lowest in toothpicks (1.19-1.57 mg/product). Nicotine levels in TFN loose leaf (1.26-9.16 mg/g) were comparable to conventional moist snuff. The pH ranged from pH 4.68 to 9.49 and per cent freebase nicotine ranged from 0.0453% to 96.7%. The freebase nicotine content was highest in nicotine pouches (2.15-16.8 mg/g) and lowest in lozenges (0.0004-0.349 mg/g). The majority of TFN products (91.4%) analysed were advertised to contain flavour components.

Conclusion: Overall, products advertised as higher strength were found to have higher nicotine content than products advertised as lower strength. The measured total nicotine content was either equal to or less than the level stated on the label, except for one product. Although TFN products may not contain tobacco lamina and may lack many harmful chemicals and carcinogens found in conventional smokeless products, freebase nicotine levels in the pouch products are elevated and could contribute to higher levels of addiction and other negative health effects.