Pick up any bottle of e-liquid from a legitimate retailer in Ireland and you will find a label carrying more information than most vapers actually read. The regulatory requirements under Irish and EU law mean that all notified e-liquid products must disclose their key specifications and ingredients on the packaging, and this information is genuinely useful for making good purchasing decisions — if you know how to interpret it. For new vapers in particular, the abbreviations and numbers on an e-liquid label can seem like a foreign language when everything is unfamiliar. This guide translates all of it into plain terms.
The PG/VG Ratio: What It Means and Why It Matters
The most prominent specification on most e-liquid bottles, alongside the nicotine concentration, is the PG/VG ratio — expressed as two numbers separated by a slash, such as 50/50 or 70/30. These numbers refer to propylene glycol (PG) and vegetable glycerin (VG), the two carrier liquids that make up the bulk of any e-liquid formulation. The ratio between them fundamentally determines the character of the vaping experience.
Propylene glycol is a thin, almost water-like liquid with a faintly sweet taste. It is highly effective at carrying and distributing flavour compounds through the liquid, which is why high-PG formulations tend to produce cleaner, more accurate flavour delivery. PG is also responsible for the throat hit — the slight scratching sensation at the back of the throat on inhalation that many ex-smokers find familiar and satisfying. Higher PG ratios produce a more pronounced throat hit. PG wicks easily through the fine cotton channels of MTL coils and pod devices.
Vegetable glycerin is a thick, viscous liquid derived from plant oils, with a mild natural sweetness. Its defining characteristic in vaping is vapour production: the higher the VG percentage, the denser and more substantial the visible vapour. High-VG liquids produce the large, smooth clouds associated with sub-ohm vaping and cloud-focused devices. VG is notably smoother on the throat than PG at equivalent nicotine concentrations, which is why high-VG liquids are comfortable at higher wattages.
The practical implication is that device compatibility and PG/VG ratio must be matched. High-VG liquids, typically seventy percent VG and above, are too viscous to wick efficiently through the narrow cotton channels of MTL coils and pod devices — using them in these devices causes dry hits, burnt cotton, and rapid coil failure. High-PG liquids, or balanced fifty-fifty formulations, work across a wider range of devices but do not deliver the cloud production that sub-ohm setups are designed for. Matching the ratio to the device type is not optional — it is fundamental to both performance and coil longevity.
Nicotine Concentration: Reading the Numbers
Nicotine concentration on an Irish e-liquid label is expressed in milligrams per millilitre, written as mg/ml or simply as a number followed by mg. The maximum permitted concentration under Irish TPD regulations is twenty milligrams per millilitre, and this is the standard ceiling for nicotine-containing products sold through legitimate channels.
Common concentrations and their typical uses: zero milligrams is zero-nicotine liquid, used either by non-smokers who enjoy vaping purely for flavour, or by vapers who have stepped down their nicotine intake to zero and want to maintain the vaping habit without ongoing dependency. Three and six milligrams are low concentrations suited to sub-ohm devices, where the large vapour volume per draw compensates for the lower concentration per millilitre. Twelve milligrams is a medium concentration used in MTL devices, particularly for lighter smokers making the switch. Eighteen and twenty milligrams are high concentrations suited to pod systems and MTL devices for heavier smokers who need robust nicotine delivery.
The concentration on the label refers to the total nicotine per millilitre of liquid, not to the amount delivered per draw. The actual nicotine delivered per session depends on the concentration, the volume vaped, and the efficiency of delivery from the specific device. This is why a high-concentration liquid in an efficient pod system can be more satisfying than a lower-concentration liquid in a sub-ohm device, even if the sub-ohm device produces far more vapour per draw.
Freebase Nicotine vs. Nicotine Salts
A label may also specify the form of nicotine used in the liquid — either freebase nicotine or nicotine salts, sometimes written as nic salts or salt nic. This distinction is more than a marketing category; it describes a genuine difference in the chemistry of the nicotine and the experience it produces.
Freebase nicotine is the original form used in e-liquids and remains the standard in most sub-ohm and shortfill products. At higher concentrations — above twelve milligrams per millilitre — freebase nicotine produces a pronounced harshness on the throat that many vapers find unpleasant. This harshness effectively limits the practical maximum concentration for freebase in MTL devices to around twelve to eighteen milligrams, depending on individual tolerance.
Nicotine salts are created by combining freebase nicotine with an organic acid, most commonly benzoic acid. The resulting salt form absorbs more rapidly through the oral mucosa and lung tissue, produces a smoother throat experience at higher concentrations, and more closely replicates the pharmacokinetic profile of cigarette nicotine delivery — a faster onset and more complete satisfaction of the craving. Nic salt liquids can be used comfortably at up to twenty milligrams in appropriate pod devices without the harshness that equivalent freebase concentrations would produce.
The label will typically specify the nicotine type if it is nic salts — freebase is the default and is not always explicitly labelled. If the bottle simply says eighteen or twenty milligrams without mentioning salt, it is most likely freebase, though checking with the retailer is worthwhile if you are unsure.
The Ingredients List: What You Are Inhaling
TPD regulations require all notified e-liquid products to list their ingredients on the packaging. The ingredients list will typically contain: propylene glycol, vegetable glycerin, flavourings (sometimes listed by specific compound, sometimes as a category), and nicotine. Some liquids also contain small quantities of water, ethyl alcohol from flavour concentrates, or pH-adjusting compounds.
Flavourings are listed either individually by compound name or collectively as a category. Products from manufacturers who invest in safety testing and transparency will often list flavouring compounds individually, which allows you to cross-reference any compounds you might have a sensitivity to. Products that list only flavourings as a generic category provide less information but are not necessarily less safe — the TPD notification process requires ingredient disclosure to the HPRA regardless of what appears on the consumer label.
Certain flavouring compounds that were used in early e-liquids have since been voluntarily removed by responsible manufacturers following emerging research. Diacetyl, a butter flavouring compound associated with severe lung disease in occupational exposure settings, was used in early e-liquids and is now absent from products supplied by reputable manufacturers operating in the EU market. You do not need to scan for diacetyl specifically on labels of products from established brands, as its removal from compliant products has been comprehensive — but it is a useful reminder of why buying from legitimate, regulated sources matters.
Volume and Bottle Size
The volume of liquid in the bottle is expressed in millilitres on the label. The most common sizes for nicotine-containing e-liquid sold in Ireland are ten millilitres, which is the maximum bottle size permitted for nicotine-containing liquid under TPD regulations. Larger bottles — fifty millilitres, one hundred millilitres — contain zero nicotine and are sold as shortfill bases, designed to be combined with a separately purchased nicotine shot.
The bottle size is therefore a quick indicator of whether the liquid contains nicotine or not. A fifty millilitre bottle that claims to contain nicotine is either non-compliant with TPD regulations or is structured as a shortfill with a very different fill level than a standard shortfill — either way, it warrants scrutiny before purchase. Compliant nicotine-containing products in Ireland come in ten millilitre bottles.
Health Warnings and Best-Before Information
The health warning is a regulatory requirement and must cover at least thirty percent of the surface of all packaging for nicotine-containing products. The standard warning states that the product contains nicotine which is an addictive substance. If the bottle you are considering does not carry this warning, it has either not been notified to the HPRA or is missing mandatory labelling — either situation is a reason not to purchase.
The best-before date is similarly mandatory and informs you of the period within which the manufacturer guarantees the product will perform as intended under proper storage conditions. As discussed elsewhere, this is not a safety cutoff but a quality guarantee. Products stored correctly often remain perfectly usable beyond the best-before date, while products stored poorly may degrade well before it.
Reading the full label of any e-liquid before purchasing takes under a minute and gives you the information needed to confirm that the product is compliant, appropriately specified for your device, and formulated by a manufacturer who takes labelling seriously. It is a habit worth developing from your first purchase.
