title: An approach to allergy risk assessments for e-liquid ingredients.
abstract: Many flavours and fragrances are known allergens. Their selection and inclusion levels in e-liquids must therefore be guided by toxicological principles, taking into account the exposure pattern and inhalation route of exposure. For contact sensitisation, a general, agreed quantitative risk assessment approach to prevent dermal sensitisation exists. Here we propose exposure parameters and safety factors to apply this approach to e-liquid ingredients. Additionally, as a risk management approach for pre-sensitised individuals, we derive a threshold of 0.1% for indicating the presence of a contact sensitiser in e-liquid. Risk assessment for respiratory sensitisation is not well established. Occupational exposure limits that protect against respiratory allergy are generally very low. Cocoa shell extract is used as a case study to discuss the issues. A tolerable exposure level is derived and estimates of consumer exposure are presented, leading to the practical risk management approach of excluding respiratory sensitisers as e-liquid ingredients. Related to this, if natural extracts are used as flavourings in e-liquids, we recommend only protein-free versions are used. Additionally, we recommend the presence of any potential food allergens should be noted on the product information.
authors.affiliation: Nicoventures R&D, Regents Park, Southampton SO15 8TL, UK. Electronic address: sandra_costigan@bat.com.
authors.forename: Sandra
authors.initials: S
authors.lastname: Costigan
authors.affiliation: BAT R&D, Regents Park, Southampton SO15 8TL, UK. Electronic address: juan_lopez-belmonte@bat.com.
authors.forename: Juan
authors.initials: J
authors.lastname: Lopez-Belmonte
mesh_terms: D000485:Allergens / Q000009:adverse effects*; D002099:Cacao / Q000737:chemistry*; D066300:Electronic Nicotine Delivery Systems; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology*; D006969:Hypersensitivity, Immediate / Q000209:etiology; D016273:Occupational Exposure; D010936:Plant Extracts / Q000009:adverse effects*; D012130:Respiratory Hypersensitivity / Q000209:etiology; D018570:Risk Assessment
chemical_list: D000485:Allergens; D010936:Plant Extracts
keywords: Contact sensitisation; E-cigarette; E-liquid; ENDS; Flavour; Hypersensitivity; Respiratory allergy; Risk assessment