Date of Award

January 2021

Document Type


Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Paul Anastas

Second Advisor

Yasmmyn Salinas


The unprecedented rise of vaping has resulted in gaps of scientific understanding of the health hazards this new phenomenon has created, as well as delayed regulations surrounding vape products, including coolants. Coolants are additives that create anesthetic, physical sense-reducing, and/or analgesic, properties that numbs the airways and add a minty flavor to vape products. However, it is unclear how much coolant is added to vape products electronic liquid (e-liquid), and how much of this content carries over into the aerosolized vaped form. To determine compositional analysis and carryover of common synthetic coolants, eugenol in 35 clove e-liquids and menthol, methone, carvone, WS-3(N-Ethyl-2-isopropyl-5-methylcyclohexanecarboxamide; CAS no. 39711-79-0), and WS-23 (2-Isopropyl-N,2,3-trimethylbutanamide; CAS no. 51115-67-4) in 33 coolant-related e-liquids was measured using a Gas Chromatography/Flame Ionization Detector (GC/FID) in both e-liquid form (neat) and vaped form. The analysis revealed high variation quantities in eugenol with a range of 76.38 μg/mL among the 35 clove e-liquid. The synthetic coolants varied in quantity and use among the 33 coolant-related e-liquids, with WS-3 (24/33) and methone (19/33) being the most common, and WS-23 being the least common (1/33). Carryover between neat to vaped content was high at approximately 100% average carryover for all coolants, but was lower in small starting quantities starting at 2 μg/mL. Future direction would be to assess the toxicity of the coolants on human cells, with the hope that relevant information will be used to inform regulation around coolants and vaping.


This thesis is restricted to Yale network users only. It will be made publicly available on 06/01/2023