Transparency

Sources & Methodology

Version 1.0 · Published March 2026

Full sources, assumptions and calculations behind every environmental impact estimate shown in the app.

Scope & General Approach

All cigarette and disposable vape lifecycle estimates use global-average production data and represent upstream supply chain impacts: cultivation, manufacturing, materials production, packaging, and distribution.

Metrics do not include:

  • Retail infrastructure
  • Consumer transport to point of sale
  • Secondary packaging waste variability
  • Post-consumer waste treatment variability
  • Combustion emissions for cigarettes (point-of-use)

Where published ranges exist, Breathe Free With Me applies midpoint or conservative-lower estimates. The app does not generate, claim, or sell carbon offsets.

1. Climate & Air Impact

1.1 CO₂ emissions per cigarette (supply chain)

Global tobacco supply chain emissions: 84 million tonnes CO₂ annually
Cigarettes produced globally: ~6 trillion annually

84,000,000 tonnes ÷ 6,000,000,000,000 cigarettes
= 0.000000014 tonnes per cigarette
= 14 g CO₂e per cigarette

App assumption: 14 g CO₂e per cigarette avoided.

Scope covers cultivation, curing, manufacturing, packaging, and distribution. Excludes combustion emissions and consumer transport.

1.2 CO₂ emissions per disposable vape (lifecycle)

Lifecycle emissions cover: lithium-ion battery production, plastic housing,
electronic components, assembly, packaging, and distribution.

Based on published lifecycle modelling for lower-capacity devices:
= 150 g CO₂e per disposable vape

App assumption: 150 g CO₂e per disposable vape avoided.

Excludes user behaviour variability, disposal pathway differences, and regional electricity grid variation.

1.3 Emissions equivalences (illustrative comparisons only)

These comparisons translate an abstract CO₂ mass into familiar everyday scales. They are illustrative and do not imply any causal relationship between app use and reduced driving or flying.

ComparisonReported dataAssumption used
Car miles not drivenUK average passenger car: ~0.26 to 0.28 kg CO₂e per mile (2025 UK GHG conversion factors)270 g CO₂e per mile (mid-range)
Short-haul flights avoidedShort-haul economy: ~0.13 to 0.23 kg CO₂e per passenger-km. Representative distance: 1,000 km = 130 to 230 kg CO₂e.150 kg CO₂e per flight (conservative lower end)
CO₂ absorbed by treesWoodland Carbon Code: ~20 to 25 kg CO₂ per mature temperate tree per year (species and age dependent).22.5 kg CO₂ per tree per year (arithmetic mid-range)

Tree comparison is an illustrative annual absorption equivalence only. It does not represent certified carbon removal or offsetting.

2. Resource & Materials Conservation

2.1 Water use per cigarette (global footprint estimate)

Global water depletion from tobacco: 22 billion m³ annually
Cigarettes produced: ~6 trillion annually  (1 m³ = 1,000 litres)

22,000,000,000 m³ ÷ 6,000,000,000,000 cigarettes
= 0.0037 m³ per cigarette
= 3.7 litres per cigarette

App assumption: 3.7 litres water depleted per cigarette avoided.

"Water depleted" refers to freshwater consumed within the tobacco supply chain. Actual per-cigarette impact varies by region and production practice.

Volume comparison conversions used in the app: standard UK bathtub ~135 L; toilet flush ~5 L; Olympic swimming pool = 2,500,000 L.

2.2 Lithium content per disposable vape (materials indicator)

This metric reflects refined lithium content per device as a materials-demand indicator, not a lifecycle impact score.

Published range: ~0.1 to 0.3 g refined lithium per device
(varies with battery size and capacity)

App assumption: 0.15 g refined lithium per disposable vape (conservative mid-range).

This metric indicates materials demand and waste risk; it does not represent direct local environmental damage or measured release.

Comparison conversions: ~8 to 12 disposable vape batteries ≈ lithium content of 1 smartphone battery; ~150 mg lithium per wireless earbud set (earbuds + charging case).

3. Pollution & Ecosystem Protection

3.1 Cigarette filters: microfibres

Cigarette filters are primarily composed of cellulose acetate, a semi-synthetic plastic polymer. When discarded, the filter strands can detach and fragment into microplastic fibres.

Laboratory analysis: a single cigarette filter contains and/or can release
~15,000 cellulose acetate microfibre strands.

App assumption: each avoided cigarette = up to ~15,000 potential microfibres not entering the waste stream.

Represents structural potential under experimental conditions. Fragmentation rates vary by environment, temperature, UV exposure, and disposal pathway.

Microplastics comparisons (fibre-count equivalents): ~10,000 per single-use plastic straw; ~25,000 per lightweight plastic bag; ~120,000 per polystyrene cup (all illustrative).

3.2 Nicotine retained in a smoked cigarette (residual)

Reported retained nicotine:
~2.1 mg nicotine per smoked cigarette butt / filter

App assumption: each avoided cigarette = reducing potential disposal of ~2.1 mg nicotine.

Retained nicotine is not equivalent to measured aquatic concentration. Leaching depends on disposal pathway, water exposure, rainfall, and degradation environment.

3.3 Residual nicotine per disposed vape

Typical residual nicotine: ~5 mg nicotine per disposed vape
(device and user dependent)

App assumption: each avoided disposable vape = reducing potential disposal of ~5 mg nicotine.

Residual nicotine varies materially with device size, remaining e-liquid volume, and user behaviour. Used as an indicative conservative estimate.

3.4 Illustrative freshwater dilution equivalency

To express estimated nicotine mass in relatable water-volume terms, the app calculates the theoretical water volume corresponding to a published laboratory freshwater effect concentration under uniform dilution assumptions.

Reference concentration: 10 µg/L = 0.01 mg/L

Water volume (L) = Nicotine mass (mg) ÷ 0.01 mg/L

Example per cigarette butt:
2.1 mg ÷ 0.01 mg/L = 210 litres

Secondary conversions: 5 L per toilet flush, 135 L per bathtub,
2,500,000 L per Olympic pool.

3.5 Litter prevention: cigarette filter volumes

Cigarette filters are among the most commonly collected items in global beach and urban clean-up programmes.

Used for contextual litter prevalence information only.

Typical cigarette filter: Length ≈ 2.5 cm, Diameter ≈ 0.8 cm (Radius = 0.4 cm)

V = π × r² × h
V = 3.14159 × (0.4)² × 2.5
V ≈ 1.26 cm³ per filter

Container conversions (loose packing):
  240 L wheelie bin ≈ ~120,000 filters
  150 L bathtub ≈ ~75,000 filters
  4 m³ builder's skip ≈ ~2,000,000 filters

Packing estimates assume loose, uncompressed filters. Actual volume varies slightly by brand.

4. Limitations & Controls

The following limitations apply to all metrics shown in the app:

  • Global averages: all per-unit figures are global average estimates. Local production, regional water availability, energy grids, and supply chain practices vary significantly.
  • Avoided demand, not guaranteed reduction: metrics represent indicative avoided production demand and do not account for substitution effects, rebound consumption, or market-level demand responses.
  • Release is not guaranteed: microfibre and nicotine figures represent potential pollutant loads; actual environmental release depends on disposal behaviour, geography, weather, and waste treatment.
  • Equivalences are illustrative only: car mile, flight, and tree comparisons are provided as scale-of-magnitude aids, not causal connections between app use and travel or land-use changes.
  • Educational purpose: these metrics are engagement and educational tools. They do not constitute environmental performance reporting, ESG disclosure, lifecycle certification, or regulatory sustainability statements. The app does not generate, claim, or sell carbon credits or offsets.
  • Data currency: sources are reviewed annually. Conversion factors (e.g., UK Government GHG factors) are updated each year; figures in the app may reflect the version in use at time of activity.
  • Rounding: all displayed values are rounded or formatted using compact notation. Raw calculated values may differ fractionally from displayed figures.

5. Document History

VersionDateChanges
1.0March 2026Initial publication. All metrics, sources, and calculations documented for app v1.0 launch.

Questions or corrections: If you identify an error in our sources or calculations, contact us at support@breathefreewithme.com. We are committed to accuracy and will review any substantiated corrections promptly.