Small iron, steel and aluminium containers without mechanical or thermal equipment

1. Scope and Applicability

This PCR applies to the manufacture of empty iron, steel or aluminium tanks, casks, drums, cans, boxes and similar containers with a capacity not exceeding 300 litres, excluding containers for compressed or liquefied gas and excluding products fitted with mechanical or thermal equipment. It covers forming from purchased metal sheet or strip, route-specific joining, aqueous cleaning or chemical pretreatment when performed, coating, printing and curing when performed, inspection, and release at the manufacturing plant gate.

The foreground boundary begins when purchased metal feedstock, process chemicals, coating materials and utilities cross the manufacturing-site boundary. Upstream production of those inputs is represented by linked datasets. Filling with contents, distribution, use, collection and end-of-life of the container are outside this gate-to-gate foreground boundary. Separately supplied stoppers, caps, lids, closures and other packing accessories are excluded as products; a closure permanently supplied as part of the declared container must be disclosed and inventoried as its own atomic component in the foreground data package.

The method is common to covered container forms, but every dataset must declare one actual material, container form, nominal capacity, joining route, coating system and market state. The reference-flow object below is a mass-based steel-can representative; use for another covered form requires a product-specific output identity review while retaining the same mass, boundary and data-collection rules.

2. Product Category Identity

Field	Value
canonical_pcr_id	pcr.metal-products-machinery-and-equipment.fabricated-metal-products-except-machinery-and-equipment.tanks-casks-drums-cans-boxes-and-similar-containers-other-than-for-compressed-or-liquef-f53244d2
classification_refs	CPC 3.0: 42931 (exact category context)
covered_products	Empty iron, steel or aluminium tanks, casks, drums, cans, boxes and similar containers with nominal capacity not exceeding 300 L and without mechanical or thermal equipment
excluded_products	Containers for compressed or liquefied gas; containers exceeding 300 L; containers fitted with mechanical or thermal equipment; separately supplied stoppers, caps, lids and packing accessories; filled containers
representative_product	Empty steel can released at the manufacturing plant gate
production_route	Purchased metal sheet or strip; cutting and forming; conditional joining; conditional aqueous pretreatment; conditional coating, printing and curing; inspection and release
market_state	Empty, conforming, dry container at the manufacturing plant gate, with material, form, capacity, coating and closure configuration declared

3. Reference Flow

Field	Value
What	Manufacture and provide a conforming empty small metal container represented by a steel can
How much	1 kg net mass of released empty steel can
How well	Meets the declared dimensional, capacity, material, seam, coating, cleanliness and leak-tightness specification
How long or cycle	One completed manufacturing and release cycle to the plant gate; container use life is outside the foreground boundary
reference_flow_link	The released steel_can_output mass equals the 1 kg reference amount after excluding contents, transport packaging and separately supplied accessories

Field	Value
Reference amount	1 kg
Reference product flow	Steel can 5e63418a-6550-4e3c-a334-3a1b343ced44
Reference flow property	Mass 93a60a56-a3c8-11da-a746-0800200b9a66
Reference unit group	Units of mass 93a60a57-a4c8-11da-a746-0800200c9a66
Reference unit	kg
Required qualifiers	actual container material and alloy or steel grade; container form; nominal capacity in L; empty net mass; sheet or strip gauge; two-piece, three-piece, welded, seamed or drawn joining/forming route; internal and external coating system; printing route; closure supplied with container or separately; reusable or single-use market state; production geography and reporting period; released-product specification; plant-gate boundary

When constructing a foreground data package, the items listed in Required qualifiers must be declared in dataset metadata, process notes, reference flow comment, product description, or an equivalent data package field. Missing required qualifiers make the reference flow definition incomplete for that data package.

4. Measurement and Unit Rules

rule_id	Applies to	Required property	Required unit	Rule
measurement_reference_mass	reference product and mass-normalized inventory	Mass 93a60a56-a3c8-11da-a746-0800200b9a66	kg	Use the net dry mass of conforming empty containers released at the plant gate. Exclude contents, pallets, stretch wrap, cartons and separately supplied accessories.
measurement_count_to_mass	item-count production and reject records	Mass 93a60a56-a3c8-11da-a746-0800200b9a66	kg	Convert counts to mass using a contemporaneous average tare from a documented sample of the same material, form, capacity and configuration; retain sample size and dispersion.
measurement_electricity_energy	all electricity rows	Net calorific value 93a60a56-a3c8-11da-a746-0800200b9a66	MJ	Retain meter readings in kWh and convert to MJ using 3.6 MJ per kWh; do not mix purchased electricity with on-site fuel energy.
measurement_gas_volume	natural gas	Volume 93a60a56-a3c8-22da-a746-0800200c9a66	m3	State the metering reference temperature, pressure and dry/wet basis and use the supplier or meter correction to the reported volume basis.
measurement_water_mass	process water and wastewater	Mass 93a60a56-a3c8-11da-a746-0800200b9a66	kg	Prefer mass measurement. When volume is measured, convert using measured or documented density at the recorded temperature and retain both the volume record and conversion basis.
measurement_material_balance	metal feedstock, released product and metal scrap	Mass 93a60a56-a3c8-11da-a746-0800200b9a66	kg	Reconcile opening stock plus receipts minus closing stock to released product, segregated scrap, rejects and documented inventory change for each material route.

5. System Boundary

Boundary Abstraction

Field	Value
declared_starting_condition	Purchased metal sheet or strip, process chemicals, coating materials and utilities at the manufacturing-site gate, each with supplier identity, material state and upstream dataset link
starting_condition_role	Upstream product inputs to gate-to-gate foreground container manufacture
product_classification_scope	Empty iron, steel or aluminium containers not exceeding 300 L, excluding compressed/liquefied-gas containers and mechanically or thermally equipped containers
recursive_input_rule	If a covered small metal container is itself consumed as a foreground input, record that specific container as a direct product input with a separate upstream dataset; do not recursively include its manufacture inside the current foreground process
upstream_dataset_requirement	Link upstream datasets for each purchased metal feedstock, electricity supply, fuel, water, chemical, coating and joining consumable at the declared geography and delivery boundary
disclosure	Declare material and gauge, forming and joining route, pretreatment and coating route, nominal capacity, included closure configuration, plant geography, reporting period, upstream dataset choices, allocation and any excluded on-site operation

Boundary Rules

rule_id	Applies to	Rule	source_ids
boundary_gate_to_gate	foreground container manufacture	Include all on-site cutting, forming, joining, cleaning, pretreatment, coating, printing, curing, inspection, rework and release operations used for the declared container; end the foreground boundary at release of the empty container.	unsd-cpc-3-0-structure-2025; us-epa-ap42-can-coating
boundary_conditional_routes	route selection	Include joining, aqueous treatment, coating, printing and curing only when performed for the declared product, and identify each included technology and material rather than using an averaged unqualified route.	us-epa-ap42-can-coating; ec-jrc-stm-bref-2006
boundary_upstream_inputs	purchased inputs	Keep upstream production outside the foreground unit processes but require one compatible upstream dataset for every purchased product input.	ec-jrc-stm-bref-2006
boundary_direct_releases	emissions and wastes	Include measured on-site wastewater, segregated metal scrap, coating-related NMVOC and direct fossil-fuel CO2 when those exchanges cross the foreground boundary; do not duplicate emissions already embedded in upstream electricity or fuel datasets.	us-epa-ap42-can-coating; ec-jrc-stm-bref-2006

6. Process Inventory Structure

Process Map

process_id	process_name	inclusion	inclusion_condition	role	quantitative_reference
sheet_preparation_and_forming	Sheet preparation and forming	required	Always include cutting, blanking, drawing, rolling or forming operations used for the declared container	Foreground material conversion	Per 1 kg released steel can
seam_joining	Seam joining	conditional	Include when the body, ends, handles or structural parts are welded or joined with a consumed welding material	Foreground joining	Per 1 kg released steel can
aqueous_surface_pretreatment	Aqueous surface pretreatment	conditional	Include when water-based cleaning, degreasing, etching, rinsing or chemical pretreatment is performed on-site	Foreground surface preparation	Per 1 kg released steel can
coating_printing_and_curing	Coating, printing and curing	conditional	Include when internal or external coating, printing, seam lacquer or thermal curing is performed on-site	Foreground finishing	Per 1 kg released steel can
inspection_and_release	Inspection and release	required	Always include final dimensional, visual, cleanliness and leak testing plus released-product accounting	Foreground quality release	Per 1 kg released steel can

Process: Sheet preparation and forming (sheet_preparation_and_forming)

Inputs

Product flows

Tinplate steel sheet (tinplate_steel_sheet_input)

Record tin-coated steel sheet entering cutting or forming only for the tinplate route.

• Selected flow: Tinplate steel sheet
• Flow property / unit: Mass / kg
• Amount rule: Net issued mass from receiving, coil, sheet and production records, adjusted for opening and closing stock.
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_material_mass_balance
• Sources: us-epa-ap42-can-coating

Cold-rolled carbon steel sheet (cold_rolled_carbon_steel_sheet_input)

Record uncoated cold-rolled carbon steel sheet only for a declared steel route using that feedstock.

• Selected flow: Cold-rolled carbon steel sheet
• Flow property / unit: Mass / kg
• Amount rule: Net issued mass from receiving, coil, sheet and production records, adjusted for opening and closing stock.
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_material_mass_balance
• Sources: us-epa-ap42-can-coating

Aluminium sheet over 0.2 mm (aluminium_sheet_over_0_2mm_input)

Record this sheet only when the declared aluminium feedstock thickness exceeds 0.2 mm.

• Selected flow: aluminium sheet 4f197be4-7b3b-11dd-ad8b-0800200c9a66
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg
• Amount rule: Net issued mass from receiving, coil, sheet and production records, adjusted for opening and closing stock.
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_material_mass_balance
• Sources:

0.1 mm aluminium sheet (aluminium_sheet_0_1mm_input)

Record this specific thin-sheet input only when the declared route uses 0.1 mm aluminium stock.

• Selected flow: 0.1mm Al sheet c5e98422-1b9b-4e10-b3f4-3dc4e17d3989
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg
• Amount rule: Net issued mass from receiving, coil, sheet and production records, adjusted for opening and closing stock.
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_material_mass_balance
• Sources:

Forming electricity (forming_electricity_input)

Record purchased electricity consumed by cutting, presses, drawing, rolling, conveying and route-specific forming auxiliaries.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value 93a60a56-a3c8-11da-a746-0800200b9a66 / MJ
• Amount rule: Submetered electricity for included forming equipment, converted from kWh under measurement_electricity_energy.
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_process_electricity
• Sources: ec-jrc-stm-bref-2006

Waste flows

Elementary flows

Outputs

Product flows

Waste flows

Steel sheet offcuts (steel_offcut_scrap_output)

Record segregated steel blanking skeletons, edge trim and offcuts leaving the foreground process as waste.

• Selected flow: Steel scrap, offcuts ae44c4ac-bcd5-4a16-b0a5-d674ffeaab6b
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg
• Amount rule: Weighed segregated steel offcuts transferred to the documented destination.
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_material_mass_balance
• Sources:

Aluminium forming scrap (aluminium_scrap_output)

Record segregated aluminium blanking skeletons, edge trim and forming scrap leaving the foreground process as waste.

• Selected flow: Aluminium Scrap 96c5f842-ea53-419b-b1cd-c02c479efb45
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg
• Amount rule: Weighed segregated aluminium scrap transferred to the documented destination.
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_material_mass_balance
• Sources:

Elementary flows

Process: Seam joining (seam_joining)

Inputs

Product flows

Flux-cored welding wire (flux_cored_wire_input)

Record flux-cored wire only when it is physically consumed by the declared welded joining route; resistance-welded or mechanically seamed routes report this row as not applicable.

• Selected flow: Flux Cored Wire 1b74a576-06e0-4764-97ce-11a73f8a4752
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg
• Amount rule: Issued mass minus returned usable wire for container lots using flux-cored welding.
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_joining_consumables
• Sources:

Joining electricity (joining_electricity_input)

Record purchased electricity for welding, seaming and joining equipment included in the declared route.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value 93a60a56-a3c8-11da-a746-0800200b9a66 / MJ
• Amount rule: Submetered electricity for included joining equipment, converted from kWh.
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_process_electricity
• Sources:

Waste flows

Elementary flows

Outputs

Product flows

Waste flows

Elementary flows

Process: Aqueous surface pretreatment (aqueous_surface_pretreatment)

Inputs

Product flows

Process water (process_water_input)

Record externally supplied water used for aqueous cleaning, bath make-up and rinsing; exclude internally recirculated water to avoid double counting.

• Selected flow: Process Water 94a04f7e-2d5c-41f0-b182-d54a3b373a02
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg
• Amount rule: Metered net external water input, converted to mass when necessary under measurement_water_mass.
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_aqueous_pretreatment
• Sources: ec-jrc-stm-bref-2006

Sodium hydroxide (sodium_hydroxide_input)

Record sodium hydroxide as pure-equivalent product mass only when used in an alkaline cleaning or treatment bath; retain delivered solution concentration.

• Selected flow: Sodium hydroxide e0abcced-0611-4c24-9290-5a2c5a0c4169
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg
• Amount rule: Delivered solution mass multiplied by measured or supplier-declared sodium-hydroxide mass fraction.
• Value mode: Calculated value (calculated_value)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_aqueous_pretreatment
• Sources: ec-jrc-stm-bref-2006

Pretreatment electricity (pretreatment_electricity_input)

Record purchased electricity for pumps, agitation, extraction, filtration, bath controls and drying in the aqueous pretreatment process.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value 93a60a56-a3c8-11da-a746-0800200b9a66 / MJ
• Amount rule: Submetered electricity for the included pretreatment line, converted from kWh.
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_process_electricity
• Sources: ec-jrc-stm-bref-2006

Waste flows

Elementary flows

Outputs

Product flows

Waste flows

Alkaline metal-cleaning wastewater (alkaline_cleaning_wastewater_output)

Record the aqueous waste stream discharged or transferred from alkaline metal cleaning separately from other wastewater and spent concentrated bath solutions.

• Selected flow: Alkaline metal-cleaning wastewater
• Flow property / unit: Mass / kg
• Amount rule: Metered or tank-reconciled wastewater mass crossing the site boundary, with destination and treatment route recorded.
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_aqueous_pretreatment
• Sources: ec-jrc-stm-bref-2006

Elementary flows

Process: Coating, printing and curing (coating_printing_and_curing)

Inputs

Product flows

Formulated epoxy-resin container coating (formulated_epoxy_coating_input)

Record a formulated epoxy-resin coating only when it is applied to the declared container; retain solids, solvent and water fractions and do not substitute primary epoxy resin mass.

• Selected flow: Formulated epoxy-resin container coating
• Flow property / unit: Mass / kg
• Amount rule: Issued coating mass minus returned usable coating, by formulation and application line.
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_coating_fuel_and_formulation
• Sources: us-epa-ap42-can-coating

Natural gas for curing (natural_gas_input)

Record gaseous natural gas delivered to coating or curing ovens only when directly burned on-site.

• Selected flow: natural gas in the gaseous state 4f19ca0e-7b3b-11dd-ad8b-0800200c9a66
• Flow property / unit: Volume 93a60a56-a3c8-22da-a746-0800200c9a66 / m3
• Amount rule: Corrected meter volume assigned to the included coating and curing line.
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_coating_fuel_and_formulation
• Sources: us-epa-ap42-can-coating

Coating-line electricity (coating_electricity_input)

Record purchased electricity for coating application, printing, ventilation, controls, conveying and electrically heated curing equipment.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value 93a60a56-a3c8-11da-a746-0800200b9a66 / MJ
• Amount rule: Submetered electricity for the included coating, printing and curing line, converted from kWh.
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_process_electricity
• Sources: us-epa-ap42-can-coating

Waste flows

Elementary flows

Outputs

Product flows

Waste flows

Elementary flows

Non-methane volatile organic compounds to air (nmvoc_emission_output)

Record direct non-methane volatile organic compounds released from coating application, printing and curing after capture and control; exclude upstream emissions.

• Selected flow: non-methane volatile organic compounds 08a91e70-3ddc-11dd-a302-0050c2490048
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg
• Amount rule: Site-measured release or coating-line solvent mass balance after documented capture, recovery and destruction.
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_direct_air_emissions
• Sources: us-epa-ap42-can-coating

Fossil carbon dioxide to air (fossil_carbon_dioxide_output)

Record direct fossil carbon dioxide from on-site natural-gas combustion for coating or curing; exclude upstream fuel-supply and purchased-electricity emissions.

• Selected flow: carbon dioxide (fossil) 08a91e70-3ddc-11dd-923d-0050c2490048
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg
• Amount rule: Site-measured direct stack release allocated to the included curing equipment.
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_direct_air_emissions
• Sources: us-epa-ap42-can-coating

Process: Inspection and release (inspection_and_release)

Inputs

Product flows

Inspection and release electricity (inspection_electricity_input)

Record purchased electricity for leak testing, dimensional inspection, vision systems, dry cleaning, conveying and dispatch preparation.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value 93a60a56-a3c8-11da-a746-0800200b9a66 / MJ
• Amount rule: Submetered electricity for inspection and release equipment, converted from kWh.
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_process_electricity
• Sources:

Waste flows

Elementary flows

Outputs

Product flows

Released steel can (steel_can_output)

Record only conforming empty steel cans released at the plant gate; other covered product forms require their own reviewed product-flow identity.

• Selected flow: Steel can 5e63418a-6550-4e3c-a334-3a1b343ced44
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg
• Amount rule: Net dry mass of conforming empty steel cans released during the reporting period.
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: 1 kg released steel can
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_released_product
• Sources: unsd-cpc-3-0-structure-2025

Waste flows

Elementary flows

7. Allocation and Co-product Handling

rule_id	Applies to	Rule	source_ids
allocation_avoid_by_subdivision	all foreground processes	Avoid allocation by separating material routes, product forms, lines, batches, meters, tanks and emission controls wherever records permit.	ec-jrc-stm-bref-2006
allocation_shared_utilities	shared electricity, fuel, water and treatment services	Assign directly metered quantities first. If direct measurement is unavailable, use a documented physical driver such as equipment time, treated surface area or throughput mass; disclose the driver and sensitivity.	ec-jrc-stm-bref-2006
allocation_metal_scrap	steel and aluminium scrap	Report segregated scrap as waste output with measured mass and destination. Do not apply an avoided-primary-material credit inside the foreground inventory; any recycling substitution belongs to the declared downstream system model.	ec-jrc-stm-bref-2006
allocation_rework_and_rejects	internal rework and rejected containers	Keep internal rework loops inside the foreground system and include their incremental material and energy. Report only waste that crosses the boundary; do not count reworked mass as additional released product.	us-epa-ap42-can-coating

8. Foreground Data Collection, Calculation, and Quality Rules

Data Collection Protocols

protocol_id	process_id	flow_role	record_type	raw_fields	collection_method	unit	frequency	temporal_coverage	site_scope	aggregation_rule	quality_evidence
cp_material_mass_balance	sheet_preparation_and_forming	metal sheet inputs and segregated scrap	purchase, coil/sheet issue, stock, scale and waste-transfer records	material identity; alloy or grade; coating; thickness; opening stock; receipts; issued mass; closing stock; scrap mass; destination; lot	calibrated scales and reconciled inventory ledger	kg	each receipt, issue and waste transfer; monthly reconciliation	full reporting period	all included lines and stores	reconcile separately by material and product route, then normalize to released mass	scale calibration; supplier certificate; inventory close; waste transfer note
cp_process_electricity	all included processes	purchased electricity	submeter and production records	meter id; start/end reading; kWh; process; line; lot; operating time; shared-load driver	calibrated submeter or documented main-meter subtraction	kWh	continuous or each shift; monthly close	full reporting period	all included production and auxiliary equipment	subtract excluded loads, allocate shared loads by documented physical driver, convert to MJ and normalize	meter calibration; single-line diagram; reconciliation to invoice
cp_joining_consumables	seam_joining	flux-cored wire	issue, return and batch records	consumable identity; grade; diameter; issued mass; returned mass; lot; joining technology; product lot	calibrated issue scale and stores ledger	kg	each issue and return	full reporting period	all included joining lines	net consumption by compatible joining route, normalized to released mass	material certificate; scale calibration; batch traceability
cp_aqueous_pretreatment	aqueous_surface_pretreatment	water, sodium hydroxide and wastewater	water meter, chemical issue, bath analysis, tank and discharge records	water volume or mass; density; chemical solution mass; concentration; bath inventory; discharge mass; destination; line; lot	calibrated meters/scales, bath analysis and tank reconciliation	kg; m3; mass fraction	each batch or continuous meter; each discharge	full reporting period	all included aqueous treatment and rinse stages	keep external water, each chemical and each waste stream separate; normalize net boundary-crossing mass	meter/scale calibration; analysis result; discharge manifest; bath balance
cp_coating_fuel_and_formulation	coating_printing_and_curing	coating and natural gas	formulation, coating issue/return, gas meter and production records	formulation id; coating mass; returned mass; solids; water; solvent; gas volume; reference conditions; line; lot; coated area	calibrated scale and corrected gas meter	kg; m3	each coating lot and shift; monthly close	full reporting period	all included coating, printing and curing equipment	aggregate only identical formulations and route conditions; normalize to released mass	safety/technical data sheet; scale and meter calibration; lot traceability
cp_direct_air_emissions	coating_printing_and_curing	NMVOC and fossil CO2	stack test, continuous monitor, capture/control and operating records	pollutant; concentration; flow; duration; coating solvent input; capture; recovery; destruction; fuel; line; lot	site measurement or reconciled line-specific mass balance after control	kg	each test and operating period required by site plan	representative full reporting period	all direct exhausts from included coating and curing equipment	sum direct releases after control; exclude upstream electricity and fuel-supply emissions	method report; calibration; control-device log; completeness reconciliation
cp_released_product	inspection_and_release	released steel can	production, inspection, tare and dispatch records	product id; material; form; capacity; coating; closure; count; sampled tare; released mass; rejects; rework; date	calibrated production scale or count-to-mass protocol plus signed release	kg; item	each released lot	full reporting period	all included inspection and dispatch points	sum conforming released mass only; reconcile rejects and rework	scale calibration; tare sample; inspection result; release authorization; dispatch record

Calculation Rules

rule_id	Applies to	Formula or rule	Inputs	Output	source_ids
calc_normalize_reference_mass	every inventory row	normalized amount = reporting-period exchange amount / reporting-period released steel-can mass	exchange amount; released mass	amount per 1 kg released steel can
calc_electricity_mj	all electricity rows	electricity MJ = metered kWh × 3.6 MJ/kWh	metered kWh	electricity in MJ
calc_sodium_hydroxide_pure	sodium hydroxide	pure-equivalent NaOH mass = delivered solution mass × measured or supplier-declared NaOH mass fraction	solution mass; NaOH mass fraction	kg NaOH	ec-jrc-stm-bref-2006
calc_count_to_mass	released product when counted	released mass = conforming item count × contemporaneous average sampled tare	conforming count; sampled tare; sample statistics	kg released product
calc_metal_balance	each metal route	imbalance = opening stock + receipts - closing stock - released product - segregated scrap - other documented outputs; investigate and disclose non-zero imbalance	stock, receipt, product and waste masses	route mass-balance result

Data Quality Requirements

requirement_id	Applies to	Requirement	Evidence
dq_product_identity	reference product	Declare material, grade/alloy, form, capacity, gauge, joining route, coating, closure configuration and released specification for every modelled product.	supplier certificate; drawing/specification; release record
dq_temporal_representativeness	all foreground data	Use one complete, representative reporting year or the full shorter production campaign; disclose shutdowns, trials and abnormal periods.	dated records; production calendar; exception log
dq_measurement_traceability	mass, energy, water and emissions	Retain meter/scale identity, calibration status, raw readings, conversion basis and responsible record owner.	calibration certificate; raw log; signed reconciliation
dq_route_separation	material and technology variants	Do not average iron/steel and aluminium routes, coated and uncoated routes, or materially different forming/joining technologies without disclosing composition and testing sensitivity.	route-specific batch and meter records
dq_completeness	foreground boundary	Reconcile metal mass, purchased energy, water, chemicals, coating, waste and direct releases to the included process map and explain missing or estimated records.	signed mass/energy balance and completeness checklist
dq_upstream_compatibility	upstream product inputs	Use upstream datasets compatible with declared geography, technology, product state and delivery boundary; document substitutions.	upstream dataset metadata and selection record

9. Validation Rules

rule_id	Applies to	Rule	source_ids
validation_scope_identity	product category and reference flow	Fail validation if the product is for compressed or liquefied gas, exceeds 300 L, includes mechanical or thermal equipment, is filled, or lacks the required product qualifiers.	unsd-cpc-3-0-structure-2025
validation_reference_mass	reference product	Confirm that exactly 1 kg net mass of conforming released empty steel cans is the reference and that contents, transport packaging and separately supplied accessories are excluded.
validation_process_alignment	process map and inventory	Confirm every required process has a detailed inventory, every conditional process states applicability, and every selected flow is one atomic exchange.	us-epa-ap42-can-coating; ec-jrc-stm-bref-2006
validation_uuid_and_units	UUID-bearing rows	Confirm public state 100, English and Chinese baseName, flow type, classification, property, unit group and reference unit match the selected row; keep unresolved rows UUID-empty.
validation_balance_and_completeness	foreground records	Confirm material-balance closure, released-product reconciliation, route-specific utility coverage, wastewater destination and direct-emission completeness; investigate unexplained gaps.	ec-jrc-stm-bref-2006
validation_no_double_counting	emissions and recycling	Confirm upstream electricity and fuel emissions are not repeated as direct releases and no avoided recycling credit is embedded in foreground scrap outputs.

10. Published Dataset Profile

Field	Value
dataset_role	secondary_dataset; may serve as background_dataset only for the declared material, product form, capacity, route, geography and plant-gate boundary
downstream_use	Foreground process datasets and lifecycle models requiring manufacture of empty small metal containers
allowed_use	Comparison or modelling within the declared material, form, capacity, joining, coating, geography and reporting-period qualifiers
excluded_use	Compressed/liquefied-gas containers; containers above 300 L; equipped containers; filled packaging systems; a different material or product form without compatibility review; container use or end-of-life
required_metadata	PCR id; product and CPC context; material and grade/alloy; form; capacity; gauge; joining route; coating/printing route; closure configuration; geography; reporting period; reference mass; process applicability; upstream dataset links; allocation; data quality
required_quality_disclosure	Raw-record coverage; calibration; mass-balance result; count-to-mass sampling; route separation; shared-service allocation; direct-emission method; unresolved UUIDs; missing independent range evidence
update_trigger	Material, gauge, forming/joining technology, coating formulation or control, fuel, capacity class, closure configuration, site geography, allocation, upstream dataset, reporting period or released-product specification changes materially

11. Data Sources

Source id	Type	Reference	Used for
unsd-cpc-3-0-structure-2025	dataset	United Nations Statistics Division, CPC Version 3.0 Structure, 30 June 2025, https://unstats.un.org/unsd/classifications/Econ/Download/In%20Text/CPC_Ver_3.0_Structure_30Jun2025.csv (retrieved 2026-09-04)	Official CPC 42931 identity, capacity limit and exclusions
us-epa-ap42-can-coating	official_guidance	U.S. EPA, AP-42 Section 4.2.2.2, Can Coating, https://www.epa.gov/sites/default/files/2020-10/documents/c4s02_2b.pdf (retrieved 2026-09-04)	Two-piece and three-piece can route decomposition, sheet coating, forming, seam coating, curing and direct NMVOC collection requirement
ec-jrc-stm-bref-2006	official_guidance	European Commission Joint Research Centre, Reference Document on Best Available Techniques for the Surface Treatment of Metals and Plastics, August 2006, https://bureau-industrial-transformation.jrc.ec.europa.eu/sites/default/files/2019-11/stm_bref_0806.pdf (retrieved 2026-09-04)	Aqueous pretreatment, rinsing, energy, water, alkali, wastewater, waste segregation and foreground quality rules