• Home
  • Search Results
  • Evaluation of electronic cigarette liquids and aerosol for the presence of selected inhalation toxins.

Evaluation of electronic cigarette liquids and aerosol for the presence of selected inhalation toxins.

Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco (2014-09-03)
Konstantinos E Farsalinos, Kurt A Kistler, Gene Gillman, Vassilis Voudris
ABSTRACT

The purpose of this study was to evaluate sweet-flavored electronic cigarette (EC) liquids for the presence of diacetyl (DA) and acetyl propionyl (AP), which are chemicals approved for food use but are associated with respiratory disease when inhaled. In total, 159 samples were purchased from 36 manufacturers and retailers in 7 countries. Additionally, 3 liquids were prepared by dissolving a concentrated flavor sample of known DA and AP levels at 5%, 10%, and 20% concentration in a mixture of propylene glycol and glycerol. Aerosol produced by an EC was analyzed to determine the concentration of DA and AP. DA and AP were found in 74.2% of the samples, with more samples containing DA. Similar concentrations were found in liquid and aerosol for both chemicals. The median daily exposure levels were 56 μg/day (IQR: 26-278 μg/day) for DA and 91 μg/day (IQR: 20-432 μg/day) for AP. They were slightly lower than the strict NIOSH-defined safety limits for occupational exposure and 100 and 10 times lower compared with smoking respectively; however, 47.3% of DA and 41.5% of AP-containing samples exposed consumers to levels higher than the safety limits. DA and AP were found in a large proportion of sweet-flavored EC liquids, with many of them exposing users to higher than safety levels. Their presence in EC liquids represents an avoidable risk. Proper measures should be taken by EC liquid manufacturers and flavoring suppliers to eliminate these hazards from the products without necessarily limiting the availability of sweet flavors.

MATERIALS
Product Number
Brand
Product Description

Supelco
Tetrahydrofuran, analytical standard
Supelco
Tetrahydrofuran, Selectophore, ≥99.5%
Supelco
2,3-Pentanedione, analytical standard
Sigma-Aldrich
2,3-Pentanedione, natural, ≥96%, FG
Sigma-Aldrich
Tetrahydrofuran, contains 250 ppm BHT as inhibitor, ACS reagent, ≥99.0%
Sigma-Aldrich
Tetrahydrofuran, anhydrous, ≥99.9%, inhibitor-free
Sigma-Aldrich
2,3-Pentanedione, ≥96%, FCC, FG
Sigma-Aldrich
Tetrahydrofuran, suitable for HPLC, ≥99.9%, inhibitor-free
Sigma-Aldrich
2,3-Pentanedione, 97%
Sigma-Aldrich
Phosphoric acid solution, 85 wt. % in H2O, FCC, FG
Sigma-Aldrich
Phosphoric acid solution, NMR reference standard, 85% in D2O (99.9 atom % D), NMR tube size 4.2 mm × 8 in. , WGS-5BL Coaxial NMR tube
Sigma-Aldrich
2,3-Butanedione, 97%
Sigma-Aldrich
Tetrahydrofuran, anhydrous, contains 250 ppm BHT as inhibitor, ≥99.9%
Sigma-Aldrich
Phosphoric acid solution, NMR reference standard, 85% in D2O (99.9 atom % D), NMR tube size 5 mm × 8 in.
Sigma-Aldrich
Phosphoric acid solution, NMR reference standard, 85% in D2O (99.9 atom % D), NMR tube size 3 mm × 8 in.
Supelco
2,3-Butanedione, analytical standard
Sigma-Aldrich
Tetrahydrofuran, contains 250 ppm BHT as inhibitor, puriss. p.a., ACS reagent, reag. Ph. Eur., ≥99.9%
Supelco
Tetrahydrofuran, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Tetrahydrofuran, inhibitor-free, suitable for HPLC, ≥99.9%
Sigma-Aldrich
Tetrahydrofuran, contains 250 ppm BHT as inhibitor, ACS reagent, ≥99.0%
Sigma-Aldrich
Tetrahydrofuran, ACS reagent, ≥99.0%, contains 250 ppm BHT as inhibitor
Sigma-Aldrich
Tetrahydrofuran, ReagentPlus®, ≥99.0%, contains 250 ppm BHT as inhibitor
Sigma-Aldrich
Pyridine, puriss. p.a., ACS reagent, reag. Ph. Eur., ≥99.5% (GC)
Sigma-Aldrich
Pyridine, biotech. grade, ≥99.9%
Sigma-Aldrich
Phosphoric acid, ACS reagent, ≥85 wt. % in H2O
Sigma-Aldrich
Pyridine, ACS reagent, ≥99.0%
Sigma-Aldrich
Phosphoric acid, puriss. p.a., crystallized, ≥99.0% (T)
Sigma-Aldrich
Phosphoric acid, puriss. p.a., ACS reagent, reag. ISO, reag. Ph. Eur., ≥85%
Sigma-Aldrich
Pyridine, ReagentPlus®, ≥99%
Sigma-Aldrich
Pyridine, suitable for HPLC, ≥99.9%