A consumer health risk assessment of e-liquid containers

Client

A US manufacturer and supplier of container closure systems designed for e-liquids.

Background

In order to inform e-liquid manufacturers of any hazardous chemicals that may potentially leach from the containers into their e-liquid formulations for Premarket Tobacco Product Application (PMTA) submissions to the US Food and Drug Administration (FDA), extraction studies of the various containers, inner closures and nozzles were conducted. Moreover, the human health risks associated with exposure to these extractables/potential leachables was of interest to the client.

Project goals

Bibra was therefore asked to assess the health risks posed to consumers by exposure to the (organic and inorganic) chemicals identified in the extractables studies.

Approach

As various e-liquid consumer use patterns are possible, bibra considered both typical and extreme (worst-case) exposure scenarios in order to estimate potential consumer exposures to each of the extractables.

Bibra evaluated the critical systemic toxicology for each identified extractable, and also considered the risks of respiratory tract irritation. When genotoxicity could be excluded, appropriate systemic effects points of departure (PoDs) were identified from Expert Group reviews, the primary literature, or using threshold of toxicological concern (TTC) concepts. These PoDs were used to derive inhalation-specific Tolerable Intake (TI) values, in accordance with ISO 10993-17 and ICH guidelines.

Conclusions on tolerability could then be drawn by calculating the Margin of Safety (MoS) between the TI value and the estimated exposure levels.

Project outcome

By comparing the highest anticipated concentration of these potential leachables within each inhalation with tolerable concentrations (TCs) of a potent respiratory tract irritant (formaldehyde), it was concluded that respiratory tract irritation was of no practical concern.

No concerns for genotoxicity were raised by any of the assessed chemicals, and appropriate TI figures were derived. The resulting MoS were determined to be greater than unity for each extractable (or group of structurally-related extractables), thus demonstrating tolerability.

Bibra project team

Charles Johnson
Beth O’Connell
Pete Watts
Richard Young

 

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