Vaping Knowledge Index – Letter E
Browse Glossary by Letter
Estimated reading time: 12–14 minutes
Technical level: Intermediate to Advanced
Audience: Adult users (18+) in Ireland
Technical Definition (AEO)
Letter E vaping terminology covers e-liquid composition and stability, evaporation dynamics, electrical efficiency, excise taxation context (Ireland), and end-of-life disposal responsibilities.
Terms Beginning with E
E-Liquid
E-liquid is the formulated solution vaporised by a heating element. It typically contains propylene glycol (PG), vegetable glycerine (VG), flavour compounds and optionally nicotine. Composition influences viscosity, vapour density and coil longevity.
E-Liquid Ratio (VG/PG)
The VG/PG ratio defines viscosity and aerosol behaviour. Higher VG generally increases vapour density but requires efficient wicking and sufficient airflow. Higher PG typically improves flavour transmission and increases perceived throat sensation.
E-Liquid Stability (Shelf Life)
E-liquid stability refers to how the liquid’s colour, flavour and (where applicable) nicotine integrity change over time. Exposure to oxygen, light (UV) and heat accelerates chemical change. Nicotine can oxidise, causing gradual darkening and potential flavour shift; flavour compounds may also degrade under prolonged heat/UV exposure.
- Temperature stability: store in cool, stable conditions (avoid heat spikes).
- Light control: limit UV exposure (sunlight accelerates degradation).
- Oxygen minimisation: keep bottles tightly sealed; reduce headspace in partially used bottles.
In Ireland, where excise duty affects nicotine products, correct storage practices reduce quality loss for users who purchase larger volumes.
Evaporation Rate
Evaporation rate is the speed at which e-liquid converts to aerosol. It depends on coil temperature, airflow cooling, wick saturation, and VG/PG ratio. When evaporation outpaces liquid transport (capillary feed), dry hits are more likely.
Electrical Resistance
Electrical resistance (Ω) influences current demand and heating behaviour. Lower resistance coils generally draw more current at the same voltage and can increase thermal load if airflow and wicking are insufficient.
Efficiency (Electrical / Ohmic Efficiency)
Electrical efficiency describes how effectively energy drawn from the battery is converted into useful heat at the coil. Losses may occur through internal resistance, chipset conversion, wiring/contact resistance, and heat dissipated into the device body.
- Higher efficiency can improve output consistency and reduce battery strain.
- Lower efficiency may increase wasted energy and accelerate warm-up inconsistencies.
Excise Duty (Ireland)
Excise duty is a taxation framework applied to certain nicotine-related products in Ireland. In practice, excise structure impacts pricing, purchasing patterns and how users plan consumption.
EPT (E-Liquid Products Tax)
EPT refers to Ireland’s excise structure applied per millilitre for relevant nicotine liquid products. This can influence bottle formats and makes reduced waste/efficient device-liquid matching more important.
EU-CEG
EU-CEG (European Common Entry Gate) is the EU notification system used for product submissions/notifications for nicotine-containing products before legal sale within EU member states.
End-of-Life Disposal (Ecological Disposal)
End-of-life disposal refers to responsible handling of used batteries and electronic components under WEEE principles. Batteries and electronics should be recycled via authorised Irish channels rather than disposed of in household waste.
Quick MATRIX: Storage & Stability Factors
| Factor | What it changes | Typical visible signs | Practical recommendation |
|---|---|---|---|
| Heat | Accelerates oxidation and flavour degradation | Faster colour change; weaker top-notes | Store cool; avoid cars/windowsills |
| Light (UV) | Breaks down sensitive compounds | Taste dulling; gradual darkening | Keep in drawers/cabinets; avoid sunlight |
| Oxygen exposure | Promotes oxidation of nicotine and some flavour components | Darkening; possible flavour shift | Seal tightly; reduce headspace |
Safety & Compliance Notes (Ireland)
- 18+ only: This content is intended for adult users in Ireland.
- Regulatory context: Nicotine product notification frameworks (EU-CEG) apply where relevant.
- Environmental responsibility: Dispose of batteries and electronic waste through authorised Irish WEEE channels.
FAQ
Does e-liquid “expire”?
E-liquid quality typically changes gradually rather than expiring instantly. Oxidation and flavour degradation can occur over time, especially with heat, light and oxygen exposure.
Why does e-liquid sometimes darken?
Darkening is commonly linked to oxidation processes and ingredient changes over time. It may coincide with flavour shift, particularly when stored warm or exposed to light.
What does electrical efficiency mean in a vape device?
Electrical efficiency refers to how much of the battery’s energy becomes useful heat at the coil versus energy lost through conversion, wiring resistance and heat dissipation.
How should batteries be disposed of in Ireland?
Rechargeable batteries should be recycled through authorised Irish WEEE battery collection points and not placed in general household waste.
Intent Discloser
This page provides neutral technical educational information for adult users (18+) in Ireland. It does not promote specific products.