FEATURE
Eliminating unsafe ingredients from e-liquids
The importance of e-liquid avour safety assessment
Sam
Flavourings are an important part of the vaping experience.
A range of avour ingredients may be considered for use, therefore it
is important to have a process to identify ingredients with potential
toxicological concerns so they can be avoided 1 .
Ingredients with particular known toxicological hazards, such as compounds that can cause cancer, reproductive
toxicity or chemical asthma should be excluded. Maximum use levels in an e-liquid need to be established based on
scientiic data 2 . Also, how ingredients might change due to the vaping process should be considered. The e-cigarette
emissions should be assessed as well as the e-liquid. Sandra and Sam will explain just three examples where
ingredients did not meet all those assessments:
.
1
Citric acid is ‘generally recognised as safe’ in the USA and is used in
pharmaceutical inhalation products. However, thermal degradation of
citric acid can occur at the operating temperatures of some vaping
devices to form respiratory sensitisers—chemicals that, on inhalation, can
cause chemical asthma.
Acid anhydrides were detected in a
cig-a-like product but not in a modern open tank
product. It is therefore recommended to screen for
acid anhydrides before commercialising e-liquids
containing citric acid 3 .
Scientiic data supporting the recommendations
1
2
3
4
5
Holton, S. and Costigan, S. “Case studies highlighting the importance of e-liquid avour stewardship”. Poster@ Global Forum on Nicotine, June 15-17, 2017, Warsaw, Poland
Costigan, S. and Meredith, C. An approach to ingredient screening and toxicological risk assessment of avours in e-liquids. 2015. Reg. Tox. Pharm. 72, 361-369
Costigan, S. “Citric acid – a precursor to a respiratory sensitiser in e-cigarettes?” Poster@ British Tox. Society Annual Meeting, April 3-5, 2017, Liverpool, UK
Costigan, S. and Lopez-Belmonte, J. An approach to allergy risk assessments for e-liquid ingredients. 2017. Reg. Tox. Pharm. 87, 1-8
Vas, C. et al. “Acetoin is a precursor to diacetyl in e-cigarettes liquids”. Poster@ Global Forum on Nicotine, June 17-18, 2016, Warsaw, Poland
28 ISSUE 12 VAPOUROUND MAGAZINE