Fundamentals of E-cigarette E-liquid

I. What are e-liquid products?

E-cigarette e-liquid: English: E-liquid

A specialized liquid formulated with PG and VG as the base, combined with flavorings, cooling agents, sweeteners, alcohol (optional), and nicotine (optional), which is vaporized via a vaporizer to produce steam for inhalation.

Basic composition: PG + VG + flavorings & fragrances + cooling agents + sweeteners + alcohol (optional) + nicotine (optional)

The primary ingredients of SONG VAPE e-liquid are plant-based glycerol, propylene glycol, food flavorings, and nicotine salts; apart from the nicotine salts, all other components are commonly used food additives in daily life.

II. Core Base: PG & VG

1. Propylene glycol (PG)

Propylene Glycol

Features: low viscosity, rapid oil conductivity, and strong hygroscopicity

Functions: flavor carrier, provides a throat-cleansing sensation, and ensures smooth oil delivery.

2. Plant Glycerin VG

Vegetable Glycerin

Characteristics: high viscosity, heavy smoke, and strong hygroscopicity

Characteristics: produces a rich cloud of smoke, offers a mellow and warm palate, and possesses a natural subtle sweetness.

Both PG and VG exhibit strong hygroscopicity; they readily absorb moisture, which can lead to a loss of flavor and the formation of oil deposits. Store in a tightly sealed container in a cool, dry place, protected from light.

III. Nicotine System

1. Freebase Nicotine: Strong throat hit; suitable for DTL.

2. Nicotine Salt: Smooth throat feel and effective relief, ideal for MTL/RDL and small cigarettes.

SONG VAPE's next-generation nicotine salt technology builds upon traditional benzoate formulations by introducing innovations that retain the characteristic aroma of conventional benzoates while delivering a more refined and fresh flavor profile.

3. Natural Nicotine:

Source: Tobacco plant extract

Features: Traditional sourcing, moderate cost

Suitable for: standard market e-liquids

4. Synthetic Nicotine:

Source: Non-tobacco, synthetically produced

Key features: high purity, absence of tobacco off-flavors, and enhanced compliance

Applicable to markets with stringent regulatory frameworks, such as the European Union and the United States.

5. Concentration: (1% = 10 mg/mL)

0mg: Nicotine-free

3–6 mg: DTL heavy smoke

10–20 mg: MTL for daily smoking cessation

35–50 mg: light to heavy smokers

6. Hexamethyl risk:

It exhibits higher addictiveness, a slightly inferior taste profile compared to nicotine, and yields no detectable nicotine content; consequently, regulatory oversight has been tightened both domestically and internationally. This product is intended for use in specific countries seeking to circumvent nicotine-related regulatory requirements.

7. Zero Nicotine:

0 mg/mL, nicotine-free, with poor throat sensation; suitable for use in certain countries to circumvent nicotine regulations.

IV. Flavor System: flavorings, cooling agents, sweeteners

1. Flavorings

Select the primary flavor profile (tobacco, fruit, mint, etc.) to diversify the flavor options for vaporizing pods.

Food-grade = inhalation safety; must comply with TPD/FDA standards.

2. Cooling Agents

Mainstream: WS-23, WS-3, Menthol

Effects: Refreshing, counteracting excessive sweetness, and reducing irritation; excessive use may lead to dry throat.

3. Sweeteners

Commonly used: sucralose, ethyl maltol, acesulfame potassium

Function: Enhances smoothness and masks astringency and bitterness; excessive use may lead to burning of the core, carbonization, and oil overheating.

Strictly prohibited: compounds that may cause respiratory tract damage, such as diacetyl and butandione.

V. Alcohol Dilution: Purpose, Types, Compliance, and Risks

1. Why add alcohol (ethanol)?

Dilute high-viscosity e-liquid: if the e-liquid with high VG content is too viscous and has slow oil delivery, add alcohol to reduce viscosity and improve oil delivery.

Flavoring solvent carrier: dissolves poorly soluble flavor molecules to enhance flavor uniformity

Stability and corrosion resistance: A small amount of alcohol can inhibit bacterial growth and extend the shelf life.

Adjust throat sensation: slightly intensify the throat hit to approximate the authentic cigarette experience.

Effect on flavor: prolonged storage accelerates the evaporation of alcohol, which can easily lead to flavor degradation.

2. Common Types and Dosages

Primarily uses food-grade ethanol.

Standard addition: 1%–5% (industry standard)

EU CLP: ≤6% (substances exceeding 6% are classified as flammable hazardous substances)

Trace:

3. Compliance and Labeling Requirements

EU/New Zealand: Products with>3% alcohol content must bear the label "contains alcohol"

U.S. FDA: No limits set for now, but ingredient transparency is required

China: No specific limits are established, but food-grade raw materials and compliant filing are required.

Foreign trade exports: Must clearly specify and strictly control content levels to mitigate customs clearance risks.

4. Risks and Precautions

Respiratory irritation: Overdose may lead to cough, dry throat, and airway hypersensitivity.

Equipment impact: may accelerate rubber ring aging and cause mild corrosion of metal components.

Misjudgment in drunk driving: high-alcohol e-liquids may cause false-positive results on breath alcohol tests (within 15 minutes)

Strictly prohibited: Industrial alcohol/methanol (highly toxic; absolutely prohibited)

VI. Aspiration techniques: MTL / DTL / RDL

MTL (Mouth-to-Lung): inhale through the mouth → into the lungs, similar to smoking a cigarette; ideal for small cigarettes or high PG products.

DTL (Direct-to-Lung): Direct lung delivery, large vapor volume, ideal for high VG/low nicotine profiles.

RDL (Restricted Direct-to-Lung): mild lung restriction, intermediate between the two extremes, with a balanced and appropriate formulation.

VII. How to Assess the Flavor Quality of E-liquid

Naturally fragrant, free of artificial chemical notes; fresh and natural; well-layered with a smooth finish that is comfortable on the throat and does not cause a choking sensation.

A balanced cool and sweet profile that aligns with the climate of export markets.

Stable suction performance—no core clogging, no oil splattering, and no oil leakage.

Oil circulation is normal; no dry burning is observed.

The smoke is fine, and no significant dry mouth is experienced after smoking.