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Overview

General comment

Production covered

Flexible 2-Layer fabrication. The system boundary runs from copper-clad polyimide laminate preparation and outer-layer imaging through drilling and via formation, plating and etching, coverlay lamination, surface finishing, and electrical test.

The selected ImAg finish means excellent solderability, high conductivity, short shelf life (~10% market).

Modelling choices

Process inputs are normalized from the authored panel-area basis to one square metre of good PCB; no separate board-nesting utilization factor is applied. The 85.0% first-pass yield gross-ups all panel-process inputs to the functional unit.

This PCB family has no operational scenario because surface finish is its only configurable production choice, and no fab gas-recovery scenario applies to a panel process. This dataset is modelled with no water reuse. No reclaim rate is published for this kind of plant, so the water shown is the full fresh intake and no recycling credit has been deducted from it.

Technology
Flexible 2-Layer
Geography
Global average data from PCB manufacturer data, IPC standards, and industry literature

System boundary

System boundary - 2-Layer Flex PCB, ImAg finishSystem boundary figure: identity, gate in, entering flows, the dashed system boundary and the unit processes inside it, the reference product, emissions and waste, and below it the flows that are recorded but not quantified. No inventory quantities.2-Layer Flex PCB, ImAg finishGATE INCopper-clad laminate panels and chemicalsENTERING FLOWSElectricityWaterProcess chemicalsMaterialsSYSTEM BOUNDARYMODELLED UNIT PROCESSES, BY CLASSPCB fabricationPCB flexiblePCB imagingPCB laser drillingPCB desmearPCB electroless CuPCB ENIGPCB silkscreenEtchPCB etchingTestPCB electrical testREFERENCE PRODUCT2-Layer Flex PCB, ImAg finishFinished flexible PCB panel with surfacefinish and coverlayEMISSIONS AND WASTEEmissions to airEmissions to waterWaste routesRECORDED BUT NOT QUANTIFIEDIn scope, left out of the quantified inventoryCut off below the significance threshold, or with no background dataset available - each is listed with its reason2FLOWSsystem boundaryreference flowentering flowemission / waste

The figure groups this dataset's unit processes by class. It is not a count of manufacturing steps — each process runs over as many passes as the flow requires, and those pass counts ship with the dataset.

Download this figure (SVG)

Data quality and references

Composite DQI 1.9 Very good
Reliability
2.4
Completeness
2.6
Temporal
1.5
Geographic
2.0
Technological
1.3

Pedigree scores follow the ecoinvent data-quality matrix: 1 is the best attainable, 5 the weakest. The composite is their aggregate.

Sampling procedure
PCB manufacturer specifications, IPC standards, academic papers
Coverage status
Partial
Pedigree-scored source files
10 — the source records behind this dataset's manufacturing operations. Each carries the five pedigree axes above; the composite DQI aggregates them.

Technosphere inputs

20 flows. Quantities are not published; they ship with the dataset on Circa.

Electricity, China (CN) ElectricitykWh · -10.1% / +20.1%
Derivation basis
  • Calculated from equipment energy across all manufacturing operations, plus the facility support a board shop runs: cooling for the lamination press and the plating baths, and treatment of the water the shop discharges.

The sources below come from the manufacturing operations behind this row.

Sources (inherited)
Inherited, rolled up from the contributing process steps:
  • Nordelof 2019, DOI 10.1007/s11367-018-1491-3
  • Kewei Industries, "PCB Lamination Press Parameters."
  • AllPCB, "PCB Lamination Pressure."
  • MDPI, "PCB fabrication energy audit report," 2021
  • Kewei Industries, "Schmoll PCB Driller Specifications."
  • ESI, "5335 Via Drilling System Specifications."
  • Spectra-Physics, "UV Laser PCB Manufacturing," 2016
Background data
ecoinvent 3.12
Background dataset
electricity, medium voltage
Uncertainty
-10.1% / +20.1% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kWh
Fresh water WaterL · -34.6% / +35.6%
Derivation basis
  • Calculated from process-water demand across all manufacturing operations, plus cooling-tower makeup for the lamination press and the plating baths.

The sources below come from the manufacturing operations behind this row.

Sources (inherited)
Inherited, rolled up from the contributing process steps:
  • ResearchGate, Water use in PCB manufacturing
  • Envirowise, Water use in PCB manufacturing
  • Patent CN102286761B, Acid Copper Additives
  • Patent US5151170A, Brightener Consumption
  • SysPCB, Inner Layer Process
  • NMFRC, Electroless Nickel Stoichiometry
Background data
ecoinvent 3.12
Background dataset
tap water
Notes
Process and cleaning water
Uncertainty
-34.6% / +35.6% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
L
Sodium carbonate developer Process chemicalg · -59.9% / +350.6%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
soda ash, dense
Uncertainty
-59.9% / +350.6% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Dry Film Resist Process chemicalg · ±25%
Source citations
Background data
proxy-mapped
Background dataset
methyl methacrylate
Uncertainty
±25% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Hydrochloric acid Process chemicalg · -34.6% / +74.3%
Source citations
  • ResearchGate, Water use in PCB manufacturing
  • Envirowise, Water use in PCB manufacturing
  • Patent CN102286761B, Acid Copper Additives
  • Patent US5151170A, Brightener Consumption
  • SysPCB, Inner Layer Process
  • NMFRC, Electroless Nickel Stoichiometry
Background data
ecoinvent 3.12
Background dataset
hydrochloric acid, without water, in 30% solution state
Uncertainty
-34.6% / +74.3% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Hydrogen peroxide Process chemicalg · -34.6% / +73.8%
Source citations
  • ResearchGate, Water use in PCB manufacturing
  • Envirowise, Water use in PCB manufacturing
  • Patent CN102286761B, Acid Copper Additives
  • Patent US5151170A, Brightener Consumption
  • SysPCB, Inner Layer Process
  • NMFRC, Electroless Nickel Stoichiometry
Background data
ecoinvent 3.12
Background dataset
hydrogen peroxide, without water, in 50% solution state
Uncertainty
-34.6% / +73.8% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Potassium permanganate Process chemicalg · -81.3% / +34.1%
Source citations
Background data
ecoinvent 3.12
Background dataset
potassium permanganate
Uncertainty
-81.3% / +34.1% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Sodium hydroxide Process chemicalg · -30.3% / +45.5%
Source citations
  • ResearchGate, Water use in PCB manufacturing
  • Envirowise, Water use in PCB manufacturing
  • Patent CN102286761B, Acid Copper Additives
  • Patent US5151170A, Brightener Consumption
  • SysPCB, Inner Layer Process
  • NMFRC, Electroless Nickel Stoichiometry
Background data
ecoinvent 3.12
Background dataset
sodium hydroxide, without water, in 50% solution state
Uncertainty
-30.3% / +45.5% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Neutralizer (sulfuric acid or HCl) Process chemicalg · -20% / +50%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
sulfuric acid
Uncertainty
-20% / +50% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Copper sulfate pentahydrate Process chemicalg · -30.6% / +38.9%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
copper sulfate
Uncertainty
-30.6% / +38.9% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Formaldehyde Process chemicalg · -20% / +40%
Source citations
Background data
ecoinvent 3.12
Background dataset
formaldehyde
Uncertainty
-20% / +40% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Palladium catalyst Process chemicalg · -40% / +60%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
proxy-mapped
Background dataset
palladium
Notes
Proxy mapping uses 60% of the material mass.
Uncertainty
-40% / +60% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Silver nitrate Process chemicalg · -23.9% / +32.6%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
proxy-mapped
Background dataset
silver
Notes
Proxy mapping uses 63.5% of the material mass.
Uncertainty
-23.9% / +32.6% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Sulfuric acid Process chemicalg · ±42.9%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
sulfuric acid
Uncertainty
±42.9% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Nitric acid Process chemicalmL · ±50%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
nitric acid, without water, in 50% solution state
Uncertainty
±50% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
mL
Polyimide Core Materialg
Derivation basis
  • Calculated by the manufacturing model. The linked REEL dataset carries the upstream life cycle sources.

No source is attached to this row.

Source citations
Not stated
Background dataset
Modelled by REEL; see the upstream dataset above.
Uncertainty
No range defined.
Unit
g
Adhesive Materialg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
epoxy resin, liquid
Uncertainty
No range defined.
Unit
g
Copper Foil Materialg · -10% / +0%
Background data
proxy-mapped
Background dataset
copper, cathode
Uncertainty
-10% / +0% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Copper Plating Materialg · ±20%
Background data
ecoinvent 3.12
Background dataset
copper, cathode
Uncertainty
±20% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Coverlay Materialg
Derivation basis
  • Calculated by the manufacturing model. The linked REEL dataset carries the upstream life cycle sources.

No source is attached to this row.

Source citations
Not stated
Background dataset
Modelled by REEL; see the upstream dataset above.
Uncertainty
No range defined.
Unit
g

Outputs and waste

Wastewater Wastewaterm3 · -34.6% / +35.6%
Derivation basis
  • Calculated from the water balance: fresh-water input minus evaporation.

The sources below come from the manufacturing operations behind this row.

Sources (inherited)
Inherited, rolled up from the contributing process steps:
  • ResearchGate, Water use in PCB manufacturing
  • Envirowise, Water use in PCB manufacturing
  • Patent CN102286761B, Acid Copper Additives
  • Patent US5151170A, Brightener Consumption
  • SysPCB, Inner Layer Process
  • NMFRC, Electroless Nickel Stoichiometry
Background data
carried, no background dataset
Background dataset
No treatment route recorded for this output.
Uncertainty
-34.6% / +35.6% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
m3
Stripped photoresist Solid wasteg · ±20%
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

The sources below come from the manufacturing operations behind this row.

Sources (inherited)
Inherited, rolled up from the contributing process steps:
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of hazardous waste, hazardous waste incineration, with energy recovery
Uncertainty
±20% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Developer sludge Solid wasteg · ±20%
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

The sources below are this dataset's own bibliography. They are not tied to this row.

Source citations (dataset-level)
Inherited from this dataset's own bibliography, not tied to this row:
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of hazardous waste, underground deposit
Uncertainty
±20% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Copper from treated etchant drag-out Solid wasteg · -89.2% / +125.1%
Source citations
Background data
ecoinvent 3.12 treatment route
Background dataset
market for copper scrap, sorted, pressed
Uncertainty
-89.2% / +125.1% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Ablated dielectric debris Solid wasteg
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of inert waste, sanitary landfill
Uncertainty
No range defined.
Unit
g
Epoxy smear residue Solid wasteg · -73.9% / +195.5%
Source citations
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of inert waste, sanitary landfill
Uncertainty
-73.9% / +195.5% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Manganese sludge (filter cake) Solid wasteg · -86% / +101.2%
Source citations (dataset-level)
Inherited from this dataset's own bibliography, not tied to this row:
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of hazardous waste, underground deposit
Uncertainty
-86% / +101.2% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Copper in wastewater-treatment sludge/recovery Solid wasteg · -2.5% / +0.5%
Source citations (dataset-level)
Source citations (dataset-level)
Inherited from this dataset's own bibliography, not tied to this row:
Background data
ecoinvent 3.12 treatment route
Background dataset
market for copper scrap, sorted, pressed
Uncertainty
-2.5% / +0.5% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Routing dust (FR-4 particles) Solid wasteg · -9.4% / +3.1%
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of inert waste, sanitary landfill
Uncertainty
-9.4% / +3.1% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Copper Sludge Solid wasteg · -33.3% / +25.3%
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12 treatment route
Background dataset
market for metalliferous hydroxide sludge
Uncertainty
-33.3% / +25.3% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Neutralization Sludge Solid wasteg · -48.6% / +54.3%
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of hazardous waste, underground deposit
Uncertainty
-48.6% / +54.3% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Silver in wastewater-treatment sludge/recovery Solid wasteg · -33.3% / +66.7%
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12 treatment route
Background dataset
market for precious metal from electronics scrap, in anode slime
Uncertainty
-33.3% / +66.7% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Scrapped material (line yield) Solid wasteg · -3% / +0%
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

The sources below are this dataset's own bibliography. They are not tied to this row.

Source citations (dataset-level)
Inherited from this dataset's own bibliography, not tied to this row:
Background data
ecoinvent 3.12 treatment route
Background dataset
market for copper scrap, sorted, pressed
Notes
Calculated reject material after accounting for a manufacturing yield of 85%.
Uncertainty
-3% / +0% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g

Emissions to air

1 elementary flow released to air by this dataset's own operations. Quantities are not published; they ship with the dataset on Circa.

VOCs Emission to airg
Derivation basis
  • Authored at the model: emission factor declared by the model itself, converted from its authored unit to grams per functional unit. It is not re-derived from the process-gas inputs and no point-of-use abatement is applied to it; the model's own notes and sources carry the factor's basis

No source is attached to this row.

Source citations
Not stated
Compartment
Air (non-urban air or from high stacks)
ecoinvent 3.12 elementary flow
NMVOC, non-methane volatile organic compounds
Uncertainty
No range defined.
Unit
g

Emissions to water

7 elementary flows released to water by this dataset's own operations. Quantities are not published; they ship with the dataset on Circa.

Cu2+ Emission to waterg
Source citations
Compartment
Water (surface water)
Formula
Cu
CAS number
7440-50-8
ecoinvent 3.12 elementary flow
Copper ion
Uncertainty
A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit
g
Mn2+ Emission to waterg
Compartment
Water (surface water)
CAS number
16397-91-4
ecoinvent 3.12 elementary flow
Manganese II
Uncertainty
A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit
g
Potassium Emission to waterg
Compartment
Water (surface water)
Formula
K+
CAS number
24203-36-9
ecoinvent 3.12 elementary flow
Potassium I
Notes
K2SO4 → 2K⁺ + SO4²⁻ (ionic dissociation)
Uncertainty
A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit
g
Sulfate Emission to waterg
Compartment
Water (surface water)
Formula
SO42-
CAS number
14808-79-8
ecoinvent 3.12 elementary flow
Sulfate
Notes
K2SO4 → 2K⁺ + SO4²⁻ (ionic dissociation)
Uncertainty
A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit
g
HCHO Emission to waterg
Source citations
Compartment
Water (surface water)
CAS number
50-00-0
ecoinvent 3.12 elementary flow
Formaldehyde
Uncertainty
A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit
g
EDTA Emission to waterg
Source citations
Compartment
Water (unspecified)
Formula
C10H16N2O8
CAS number
60-00-4
ecoinvent 3.12 elementary flow
EDTA, Ethylenediaminetetraacetic Acid
Uncertainty
A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit
g
Silver (rinse wastewater) Emission to waterg
Derivation basis
  • Calculated as a release to water, from a contaminant mass balance on the process chemistry.

No source is attached to this row.

Source citations
Not stated
Compartment
Water (surface water)
Formula
Ag+
CAS number
14701-21-4
ecoinvent 3.12 elementary flow
Silver I
Uncertainty
A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit
g

Flows not quantified

2 flows are recorded for this dataset but carry no quantity — cut off below the significance threshold, or with no background dataset available. They remain inside the declared system boundary; each is listed with its reason.

Not modelled (2)

Complexing agent (EDTA or Rochelle salt) Process chemicalg · -20% / +50%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
Proprietary plating-bath additive consumed in trace quantity, recorded in this inventory. Formulations vary by supplier and no representative public production dataset exists, so the upstream burden is left unlinked rather than approximated with an unrepresentative proxy.
Uncertainty
-20% / +50% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Complexing agents (proprietary) Process chemicalg · ±50%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
Proprietary plating-bath additive consumed in trace quantity, recorded in this inventory. Formulations vary by supplier and no representative public production dataset exists, so the upstream burden is left unlinked rather than approximated with an unrepresentative proxy.
Uncertainty
±50% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g

The flows above are this dataset's own records. What follows are the scope rules set once for the whole database in the methodology report, repeated here so every dataset page carries them.

Database-wide boundary policy — applies to every REEL dataset

These boundaries are set once for the whole database, in Chapter 2 of the methodology report, and apply to this dataset wherever they are relevant to it. The excluded flows listed above are specific to this dataset.

Use phase
Product operation is outside the cradle-to-gate scope.
End-of-life treatment
Recycling and disposal are outside the cradle-to-gate scope.
Distribution and retail
The gate is a finished component ready for integration into a higher-level assembly.
Inbound transport of raw materials
Transport of purchased raw materials to the manufacturing facility is already inside the upstream "market for" datasets that users link to a background database, so it is not modelled a second time here. This does not cover freight between REEL production stages, which is modelled where a dataset authors it.
Returnable shipping containers
Where freight between production stages is modelled, the mass moved is the product itself. The shipping container (FOSB, SEMI M31) is returnable capital equipment whose per-trip share is unsourced, so its tare is excluded from the transport effort.
Photomask fabrication
A mask set's embodied burden is amortised across a high-volume production run and is not attributed per wafer. Users assessing low-volume production should add mask fabrication separately; the methodology report gives the basis for the exclusion.
Employee transport, administration and R&D overhead
Employee transportation, facility administration and R&D/pilot-production overhead are outside scope.
Capital goods
Manufacturing equipment, cleanroom construction and facility infrastructure are excluded, on the grounds of absent public data on equipment embodied energy, uncertainty in equipment lifetime and allocation, common practice in electronics LCA, and a focus on the operational inventory. Future versions may include capital goods when sufficient public data becomes available.
Precious metal recovery credits
Scrap recovery credits for precious metals are excluded pending data availability.
Wafer reclaim
Test wafers and scrap are outside the system boundary.

Inside the boundary, linked rather than modelled

Silicon ingot growth and wafer slicing
Inside the cradle-to-gate scope, but treated as upstream material inputs linked to background databases rather than modelled as REEL processes.
Freight between production stages
Where a dataset's product moves between REEL production stages - wafer fabrication to the packaging site, for example - that leg is authored as a transport service and linked to an ecoinvent freight activity. It is measured as a transport effort in tonne-kilometres, not as a mass. Route distances are authored per route class with a stated band; a lower bound of zero is a modelling statement that the two sites can be co-located, not a missing value.

Cut-off criteria

A flow is excluded from a process inventory when it contributes less than 1 % of the total mass of inputs to that unit process, or less than 1 % of its total energy input. The denominator is total process inputs, not product mass. That distinction matters in semiconductor manufacturing, where the input mass of water, chemicals and gases greatly exceeds the product mass, so the threshold removes only genuinely minor flows.

Included regardless of the cut-off

  • Perfluorocarbons (CF4, C2F6, SF6, NF3) - high GWP, EPA regulated
  • Heavy metals (Pb, Cd, Hg, Cr(VI)) - RoHS regulated, high toxicity
  • Volatile organics (photoresist solvents, PGMEA) - air quality
  • Precious metals (Au, Ag, Pd, Pt) - high embodied impacts
  • Ozone-depleting substances (legacy CFCs, HCFCs) - Montreal Protocol