Hearing aids and other appliances which are worn or carried, or implanted in the body, to compensate for a defect or disability

1. Scope and Applicability

This PCR applies to a finished appliance whose manufacturer-stated intended purpose is to compensate for a defect or disability and that is worn, carried, or implanted in the body. It covers hearing aids and other active or passive compensatory appliances supplied as finished devices. The foreground producer must identify the appliance subtype, intended compensatory function, active or passive operation, worn/carried/implantable state, configuration, power system, sterile state, geographic market, and declared service life.

Orthopaedic appliances, splints, fracture appliances, artificial body parts, general diagnostic or therapeutic equipment, medical furniture, software supplied independently, chargers or accessories supplied independently, and replacement parts supplied independently are excluded. A multi-product kit is covered only when the declared reference appliance and every included accessory are identified separately in the bill of materials. This boundary follows the CPC 48172 product identity and does not treat the classification leaf as a substitute for a product-specific bill of materials or manufacturing model (un-cpc-3-0-2025, ec-pef-2021, eu-mdr-2017-745).

2. Product Category Identity

Field	Value
canonical_pcr_id	pcr.metal-products-machinery-and-equipment.medical-appliances-precision-and-optical-instruments-watches-and-clocks.hearing-aids-and-other-appliances-which-are-worn-or-carried-or-implanted-in-the-body-to-d2e8791e
classification_refs	CPC 3.0 48172, exact contextual reference
covered_products	Finished hearing aids and other finished appliances worn, carried, or implanted in the body to compensate for a defect or disability
excluded_products	Orthopaedic appliances, splints, fracture appliances, artificial body parts, general diagnostic or therapeutic equipment, medical furniture, independently supplied software, accessories, chargers, and replacement parts
representative_product	One finished, tested, and configured compensatory appliance; the producer must state the concrete appliance subtype and included accessories
production_route	Product-specific component manufacture or procurement, final assembly, testing, packaging, and, where applicable, validated sterilization; distribution, use, maintenance, and end-of-life are conditional extensions
market_state	Finished appliance at the manufacturer gate, with sterile/non-sterile state, configuration, included accessories, and sale geography declared

3. Reference Flow

Field	Value
What	Provide the manufacturer-stated function that compensates for the declared defect or disability
How much	One finished and configured appliance for one declared user application; paired or multi-unit systems must state the number of appliance units
How well	Conforming to the manufacturer-stated intended purpose, performance specification, configuration, and applicable release tests
How long or cycle	The declared expected service life or use-cycle basis; cradle-to-gate datasets must still disclose this qualifier and must not include use-stage burdens
reference_flow_link	Net mass in kg of the one finished appliance required to realize the functional unit; included accessories and packaging are separate product inputs and are not added to net appliance mass

Field	Value
Reference amount	Product-specific net mass of one finished appliance, measured in kg
Reference product flow	Hearing aids and other appliances which are worn or carried, or implanted in the body, to compensate for a defect or disability 702d21c4-fc45-412a-8beb-e685dd9a623a
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	concrete appliance subtype; intended compensatory function; active or passive operation; worn, carried, or implantable state; unit count; net appliance mass; configuration and included accessories; power-source chemistry; sterile state and sterilization method when applicable; manufacturer-gate geography; sale geography; expected service life or use-cycle basis; cradle-to-gate or cradle-to-grave 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
reference_product_mass	reference product and mass-normalized inventory	Mass 93a60a56-a3c8-11da-a746-0800200b9a66	kg	Measure net mass of the finished appliance after final testing and before packaging; report accessory and packaging masses separately.
count_to_mass	components or cells recorded by item count	Mass 93a60a56-a3c8-11da-a746-0800200b9a66	kg	Convert counts to kg with product-specific measured unit mass and retain count, unit-mass sample, and conversion records; do not apply a generic count-to-mass factor.
electrical_energy	assembly, sterilization, and use-stage charging electricity	Net calorific value 93a60a56-a3c8-11da-a746-0800200b9a66	MJ	Record metered electricity and convert kWh to MJ using 1 kWh = 3.6 MJ; preserve meter boundary, voltage level, grid geography, and loss boundary.
service_life_normalization	conditional use and end-of-life stages	Mass and declared appliance count	kg and item	Scale use-stage exchanges to the declared number of appliance units, duty cycle, replacement schedule, and expected service life; report all four parameters.

5. System Boundary

rule_id	Applies to	Rule	source_ids
boundary_product_specific_bom	all production datasets	Use a product-specific bill of materials or bill of components and company-specific manufacturing activity data; identify each included accessory and packaging component separately.	ec-pef-2021; selhorst-et-al-2025-hearing-aid-lca
boundary_required_production	cradle-to-gate foreground system	Include component or material inputs crossing the final-manufacturing boundary, in-house forming, final assembly, testing, rejects, packaging, and applicable sterilization through release of the finished appliance at the manufacturer gate.	ec-pef-2021; selhorst-et-al-2025-hearing-aid-lca; eu-mdr-2017-745
boundary_conditional_life_cycle	cradle-to-grave extension	Include distribution, use electricity, replacement consumables, maintenance, collection, dismantling, recycling, incineration, and landfill only when the declared scope includes those stages; state geography and scenario assumptions.	ec-pef-2021; selhorst-et-al-2025-hearing-aid-lca
boundary_sterile_device	appliances supplied sterile	Include the validated sterilization operation and sterile-barrier packaging when the appliance is placed on the market sterile; disclose sterilization method and maintain the sterile state through the declared manufacturer-gate boundary.	eu-mdr-2017-745
boundary_no_hidden_cutoff	all foreground and linked upstream processes	Do not omit a material, component, energy, waste, or direct emission merely because its mass is small; quantify and disclose any justified cut-off and assess electronics, batteries, precious-metal contacts, and sterile packaging explicitly.	ec-pef-2021; selhorst-et-al-2025-hearing-aid-lca

Boundary Abstraction

Field	Value
declared_starting_condition	Purchased material or component at the point it enters the reporting manufacturer's controlled production system
starting_condition_role	Product input with upstream production represented by a linked background or supplier-specific dataset
product_classification_scope	Finished CPC 48172 compensatory appliances; components and materials retain their own product identities
recursive_input_rule	A purchased unfinished or finished appliance in the same category is recorded as a separate product input with supplier identity and mass; its upstream production is linked once and is not recreated inside the receiving process
upstream_dataset_requirement	Each purchased component, material, battery, packaging item, and energy carrier must link to a geographically and technologically representative upstream dataset; proxies are disclosed and never relabelled as exact identities
disclosure	Declare manufacturer-gate geography, product subtype, BOM revision, component make-or-buy boundary, active/passive and worn/carried/implantable state, sterile state, allocation method, cut-offs, background dataset versions, and conditional life-cycle stages included

6. Process Inventory Structure

Process Map

process_id	process_name	inclusion	inclusion_condition	role	quantitative_reference
device_assembly	Component preparation, device assembly, testing, and release	required	Always	Foreground production	Net mass of conforming finished appliance
packaging	Final product packaging	required	Always; every individual packaging component used must be added as an atomic row	Foreground production	One declared appliance sales unit
sterilization	Sterilization and maintenance of sterile state	conditional	Include only for appliances placed on the market sterile; include the actual validated route and add route-specific exchanges	Foreground production	Mass or count of sterile released appliance
use_and_maintenance	Operation and scheduled consumable replacement	conditional	Include only for cradle-to-grave scopes or a separately declared use-stage dataset	Use	Declared appliance count, duty cycle, and expected service life
end_of_life	Collection and transfer of used appliance to treatment	conditional	Include only when end-of-life is inside the declared system boundary	End-of-life	Mass of used appliance and separately removed cells

Process: Component preparation, device assembly, testing, and release (device_assembly)

Inputs

Product flows

Hearing-aid electronic module input (hearing_aid_electronic_module)

Record the populated hearing-aid electronic module when an electronically active hearing aid uses this purchased assembly. Other active appliance subtypes must add their exact electronic assembly as a separate row rather than reuse this hearing-aid-specific identity.

• Selected flow: Hearing aid electronic module assembly 7a71d9b8-bfb0-43e5-bf72-4d6455be5a2f
• Flow property / unit: Mass / kg
• Amount rule: measured accepted module mass entering assemblies that yield conforming product
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per kg net conforming finished appliance
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_assembly_bom
• Sources: selhorst-et-al-2025-hearing-aid-lca

ABS granulate for an in-house moulded housing (abs_granulate)

Record ABS granulate only when the reporting site moulds an ABS housing or other ABS appliance component. A purchased housing is instead added as its exact component product flow.

• Selected flow: Acrylonitrile-butadiene-styrene (ABS) copolymer, granulate 8f1317c1-aa51-4524-8692-74079c923e2c
• Flow property / unit: Mass / kg
• Amount rule: measured issued ABS granulate mass net of returned unopened material
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per kg net conforming finished appliance
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_assembly_bom
• Sources: ec-pef-2021; selhorst-et-al-2025-hearing-aid-lca

Medical-grade silicone earpiece or dome (silicone_earpiece_component)

Record the finished silicone earpiece or dome only for a hearing-aid configuration that includes this component. Its TianGong UUID remains unresolved; do not substitute silicon, silica, or ferroalloy identities.

• Selected flow: Medical-grade silicone hearing-aid earpiece or dome
• Flow property / unit: Mass / kg
• Amount rule: measured component mass accepted into the declared appliance configuration
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per kg net conforming finished appliance
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_assembly_bom
• Sources: selhorst-et-al-2025-hearing-aid-lca

Installed lithium-ion rechargeable button cell (lithium_ion_rechargeable_button_cell)

Record one lithium-ion rechargeable button-cell product exchange only when this chemistry and cell form are installed in the declared appliance. The exact TianGong UUID remains unresolved.

• Selected flow: Lithium-ion rechargeable hearing-aid button cell
• Flow property / unit: Mass / kg
• Amount rule: measured installed cell mass, with cell count and measured unit mass retained
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per kg net conforming finished appliance
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_assembly_bom
• Sources: selhorst-et-al-2025-hearing-aid-lca

Factory-supplied zinc-air primary button cell (zinc_air_primary_button_cell_factory)

Record zinc-air primary button cells supplied with the appliance but not included in its net mass. The exact TianGong UUID remains unresolved; zinc-manganese batteries are not accepted as a proxy.

• Selected flow: Zinc-air primary hearing-aid button cell
• Flow property / unit: Mass / kg
• Amount rule: supplied cell count multiplied by product-specific measured unit mass
• Value mode: Calculated value (calculated_value)
• Specificity: Product-specific (product_specific)
• Normalization basis: per declared appliance sales unit
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_assembly_bom
• Sources: selhorst-et-al-2025-hearing-aid-lca

Assembly and test electricity (assembly_electricity)

Record electricity crossing the final-assembly and testing meter boundary. Exclude upstream electricity already embedded in purchased component datasets.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value / MJ
• Amount rule: metered assembly and test electricity allocated to conforming appliance output using the rule in section 7
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per kg net conforming finished appliance
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_assembly_energy
• Sources: ec-pef-2021; selhorst-et-al-2025-hearing-aid-lca

Waste flows

Elementary flows

Outputs

Product flows

Conforming finished compensatory appliance (finished_compensatory_appliance)

Record the released appliance at the manufacturer gate after all required testing and, when applicable, sterilization. Packaging and separately supplied accessories are excluded from net appliance mass.

• Selected flow: Hearing aids and other appliances which are worn or carried, or implanted in the body, to compensate for a defect or disability 702d21c4-fc45-412a-8beb-e685dd9a623a
• Flow property / unit: Mass / kg
• Amount rule: measured net mass of conforming finished appliance output
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: reference flow amount
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_assembly_bom
• Sources: un-cpc-3-0-2025; eu-mdr-2017-745

Waste flows

Rejected populated printed wiring board (populated_pwb_reject)

Record populated board assemblies rejected or damaged within the foreground production boundary and transferred for treatment.

• Selected flow: Waste populated printed wiring board eb5ffe4a-49af-450c-9a31-3efdfd343f8a
• Flow property / unit: Mass / kg
• Amount rule: measured mass transferred out as populated-board waste, net of documented rework returned to production
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per kg net conforming finished appliance
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_assembly_rejects
• Sources: selhorst-et-al-2025-hearing-aid-lca

ABS injection-moulding scrap (abs_moulding_scrap)

Record separately collected ABS runners, sprues, and rejected mouldings transferred out of the foreground system. The TianGong UUID remains unresolved; generic plastic waste is not an exact identity.

• Selected flow: Waste ABS injection-moulding scrap
• Flow property / unit: Mass / kg
• Amount rule: measured ABS scrap mass transferred out, net of verified in-process regrind reused in the same reporting period
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per kg net conforming finished appliance
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_assembly_rejects
• Sources: ec-pef-2021

Elementary flows

Process: Final product packaging (packaging)

Inputs

Product flows

Paperboard sales carton (paper_box)

Record the individual paper box containing the declared sales unit. Add inserts, manuals, films, pouches, and other packaging as separate atomic rows when present.

• Selected flow: Paper box 12d5d744-7725-4dbc-b102-43c80547f777
• Flow property / unit: Mass / kg
• Amount rule: measured paper-box mass multiplied by boxes used per declared appliance sales unit
• Value mode: Calculated value (calculated_value)
• Specificity: Product-specific (product_specific)
• Normalization basis: per declared appliance sales unit
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_packaging_bom
• Sources: ec-pef-2021; selhorst-et-al-2025-hearing-aid-lca

Waste flows

Elementary flows

Outputs

Product flows

Waste flows

Elementary flows

Process: Sterilization and maintenance of sterile state (sterilization)

Inputs

Product flows

Ethylene oxide sterilant (ethylene_oxide_sterilant)

Record ethylene oxide only for an on-site validated ethylene-oxide sterilization route. Other sterilization agents must be added as separate exact chemical rows.

• Selected flow: Ethylene Oxide a460460e-055f-4b74-9c6f-c1a0b315f31a
• Flow property / unit: Mass / kg
• Amount rule: measured sterilant mass charged to validated cycles allocated to released sterile appliance output
• Value mode: Calculated value (calculated_value)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per kg net sterile appliance released
• Basis kind: Process output (process_output)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_sterilization_records
• Sources: eu-mdr-2017-745

Sterilization electricity (sterilization_electricity)

Record metered electricity for on-site sterilization, aeration, and abatement equipment; do not include electricity already represented by an off-site sterilization supplier dataset.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value / MJ
• Amount rule: metered electricity allocated to released sterile appliance output by cycle load
• Value mode: Calculated value (calculated_value)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per kg net sterile appliance released
• Basis kind: Process output (process_output)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_sterilization_records
• Sources: ec-pef-2021; eu-mdr-2017-745

Waste flows

Elementary flows

Outputs

Product flows

Waste flows

Elementary flows

Direct ethylene oxide emission to air (ethylene_oxide_to_air)

Record measured post-abatement ethylene oxide released directly to air from the foreground sterilization process. Do not include upstream emissions embedded in the sterilant or electricity datasets.

• Selected flow: ethylene oxide fe0acd60-3ddc-11dd-a488-0050c2490048
• Flow property / unit: Mass / kg
• Amount rule: measured stack and fugitive ethylene oxide mass released after abatement
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per kg net sterile appliance released
• Basis kind: Process output (process_output)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_sterilization_records
• Sources: eu-mdr-2017-745

Process: Operation and scheduled consumable replacement (use_and_maintenance)

Inputs

Product flows

Charging electricity (charging_electricity)

Record delivered electricity only for a rechargeable appliance during the declared use period. Charger losses are included when inside the meter boundary and the grid geography is declared.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value / MJ
• Amount rule: measured or product-specific charging energy per cycle multiplied by documented charging cycles over declared service life
• Value mode: Calculated value (calculated_value)
• Specificity: Scenario-specific (scenario_specific)
• Normalization basis: per declared appliance use cycle and expected service life
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_use_scenario
• Sources: selhorst-et-al-2025-hearing-aid-lca; eu-mdr-2017-745

Replacement zinc-air primary button cells (zinc_air_primary_button_cells_use)

Record replacement zinc-air primary hearing-aid button cells only for a disposable-cell configuration. The exact TianGong UUID remains unresolved.

• Selected flow: Zinc-air primary hearing-aid button cell
• Flow property / unit: Mass / kg
• Amount rule: documented replacement-cell count multiplied by product-specific measured unit mass over declared service life
• Value mode: Calculated value (calculated_value)
• Specificity: Scenario-specific (scenario_specific)
• Normalization basis: per declared appliance use cycle and expected service life
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_use_scenario
• Sources: selhorst-et-al-2025-hearing-aid-lca; eu-mdr-2017-745

Waste flows

Elementary flows

Outputs

Product flows

Waste flows

Spent zinc-air primary button cells (spent_zinc_air_button_cells)

Record intact spent zinc-air button cells transferred from the user system to a declared collection or treatment route. The exact TianGong UUID remains unresolved; zinc scrap or slag is not an acceptable proxy.

• Selected flow: Spent zinc-air primary hearing-aid button cell
• Flow property / unit: Mass / kg
• Amount rule: documented spent-cell count multiplied by product-specific measured unit mass
• Value mode: Calculated value (calculated_value)
• Specificity: Scenario-specific (scenario_specific)
• Normalization basis: per declared appliance use cycle and expected service life
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_use_scenario
• Sources: selhorst-et-al-2025-hearing-aid-lca

Elementary flows

Process: Collection and transfer of used appliance to treatment (end_of_life)

Inputs

Product flows

Waste flows

Used compensatory appliance entering end-of-life (used_compensatory_appliance)

Record the used appliance as a specific waste input to the end-of-life system. The exact TianGong waste UUID remains unresolved; unspecified solid waste is not accepted.

• Selected flow: Used hearing aid or other compensatory appliance
• Flow property / unit: Mass / kg
• Amount rule: measured collected used-appliance mass excluding separately removed cells
• Value mode: Foreground record (foreground_record)
• Specificity: Scenario-specific (scenario_specific)
• Normalization basis: per declared appliance reaching end-of-life
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_end_of_life_records
• Sources: ec-pef-2021; selhorst-et-al-2025-hearing-aid-lca

Elementary flows

Outputs

Product flows

Waste flows

Elementary flows

7. Allocation and Co-product Handling

rule_id	Applies to	Rule	source_ids
allocation_subdivide_first	shared manufacturing and sterilization operations	Subdivide product lines, meters, work orders, and sterilization loads wherever product-specific records are available before applying allocation.	ec-pef-2021
allocation_physical_driver	remaining shared energy, utilities, and rejects	Allocate remaining shared exchanges with a documented causal physical driver such as machine time, cycle load, or measured mass throughput; do not use revenue when a causal physical driver is available.	ec-pef-2021
allocation_conforming_output	assembly and packaging	Normalize foreground exchanges to conforming released appliance output; include rejects in the process that generated them and do not divide burdens by total gross input.	ec-pef-2021
allocation_recycling_credit	recycled content and end-of-life recovery	Report recycled input, treatment burdens, recovered material, and any substitution or credit method separately; do not claim avoided virgin production without a declared, consistently applied end-of-life method.	ec-pef-2021

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_assembly_bom	device_assembly	purchased components, installed cells, supplied cells, and finished appliance	approved BOM, goods receipts, scale records, production output	part identity, chemistry, supplier, accepted quantity, unit count, sampled unit mass, finished net mass, lot, configuration	reconcile approved BOM to receipts and calibrated weighing	item and kg	each BOM revision and production lot	representative reporting year	each reporting site and product configuration	sum accepted mass and normalize to conforming net appliance mass; retain count-to-mass calculation	BOM revision, supplier specification, calibration record, lot reconciliation, release record
cp_assembly_energy	device_assembly	assembly and test electricity	submeter, machine log, production record	meter start/end, kWh, line, machine time, conforming output mass, grid geography, voltage	read calibrated submeters or reconcile machine energy logs to utility meter	kWh and MJ	each shift or batch	representative reporting year	each assembly and test line	subtract non-production periods, allocate by causal driver, convert kWh to MJ, normalize to conforming output	meter calibration, utility invoice reconciliation, production log
cp_assembly_rejects	device_assembly	populated-board rejects and ABS scrap	reject log, waste scale ticket, rework record	material identity, gross reject mass, rework return mass, transfer mass, hazardous status, destination	reconcile quality rejects to weighed waste transfers and in-process reuse	kg	each transfer and production lot	representative reporting year	each reporting site	transferred waste equals rejects minus verified rework or same-period reuse; normalize to conforming output	calibrated scale, transfer note, rework record, mass-balance check
cp_packaging_bom	packaging	paper box and other individually added packaging	packaging specification, purchase record, scale record	component identity, material, unit mass, units per sales unit, recycled content, print specification	weigh a documented sample and reconcile use to packed sales units	item and kg	each packaging revision and production lot	representative reporting year	each packing site and sales configuration	unit mass times units used, normalized to declared appliance sales unit	packaging drawing, sample record, scale calibration, packed-unit reconciliation
cp_sterilization_records	sterilization	sterilant, electricity, and direct ethylene oxide release	cycle batch record, chemical issue record, electricity meter, continuous or batch emission monitoring	cycle id, load mass, released product mass, sterilant charged and recovered, kWh, stack flow, concentration, fugitive estimate, abatement status	reconcile validated cycle records, meters, chemical inventory, and post-abatement monitoring	kg and kWh	every cycle; emissions at permit or validated monitoring frequency	representative reporting year	each sterilization and abatement system	aggregate complete cycles and normalize to released sterile output; keep stack and fugitive releases explicit	sterilization validation, batch release, meter calibration, chemical mass balance, monitoring report
cp_use_scenario	use_and_maintenance	charging electricity, replacement cells, and spent cells	product test, charger measurement, service-life record, replacement log or declared scenario	appliance count, operating hours, charge energy, charger loss boundary, charge cycles, cell chemistry, replacement count, unit mass, service life, geography	use product-specific tests or documented user/maintenance records; identify scenario data separately	item, kWh, MJ, kg, hour, year	each test or maintenance event	declared expected service life	declared user geography and appliance configuration	scale measured per-cycle exchanges by documented cycles and appliance count; reconcile supplied and spent disposable cells	test report, charger meter calibration, service-life statement, replacement record, scenario justification
cp_end_of_life_records	end_of_life	used appliance collection	collection receipt, scale record, dismantling record	appliance subtype, configuration, gross mass, removed cell mass, collection geography, destination, treatment route	weigh collected appliances and separately removed cells at custody transfer	kg	each collection or transfer	declared end-of-life scenario period	each collection geography and route	aggregate appliance mass net of separately recorded cells and normalize to appliances reaching end-of-life	calibrated scale, chain-of-custody record, treatment acceptance record

Calculation Rules

rule_id	Applies to	Formula or rule	Inputs	Output	source_ids
calc_count_to_mass	component, packaging, and cell rows using item records	mass_kg = accepted_or_used_item_count × measured_mean_unit_mass_kg; sample and configuration must match the reporting product	item count, product-specific unit-mass sample	component mass in kg per reference flow	ec-pef-2021
calc_shared_energy	assembly or sterilization energy not directly metered by product	product_energy_MJ = shared_energy_kWh × 3.6 × product_causal_driver / total_causal_driver	shared meter reading, machine time or cycle load, conforming output	allocated MJ per reference flow or process output	ec-pef-2021
calc_ethylene_oxide_release	direct ethylene oxide emission to air	released_mass = integrated post-abatement concentration × dry gas volume + documented fugitive release; use consistent temperature and pressure reference conditions	concentration, gas flow or volume, monitoring interval, fugitive estimate	kg ethylene oxide to air per sterile process output	eu-mdr-2017-745
calc_use_electricity	rechargeable appliance use	lifetime_electricity_MJ = measured_charge_energy_kWh × charge_cycles × appliance_count × 3.6	measured energy per charge, cycles, count, service life	MJ electricity per declared service-life functional unit	selhorst-et-al-2025-hearing-aid-lca
calc_replacement_cells	disposable zinc-air cell use	supplied_or_spent_mass_kg = documented_cell_count × product-specific_measured_unit_mass_kg	cell count, unit mass, appliance count, service life	kg cells per declared service-life functional unit	selhorst-et-al-2025-hearing-aid-lca

Data Quality Requirements

requirement_id	Applies to	Requirement	Evidence
dq_identity	reference product and all inventory rows	Match product subtype, chemical identity, flow type, product state, property, and unit; do not replace unresolved exact identities with broad or related flows.	approved BOM, supplier specification, TianGong state-100 UUID audit, unresolved-flow register
dq_mass_balance	assembly, packaging, and end-of-life	Reconcile accepted material and component mass to conforming output, returned material, rework, rejects, packaging, and transferred waste for the same period.	signed mass-balance worksheet, calibrated scale records, transfer notes
dq_temporal	all foreground records	Use a representative continuous 12-month period where available; otherwise disclose the shorter period, seasonality, campaigns, and extrapolation.	dated meter extracts, production calendar, invoices, batch logs
dq_technology	assembly, sterilization, power system, and use	Record product configuration, BOM revision, cell chemistry, manufacturing line, sterilization route and abatement, charger technology, and duty cycle; do not combine incompatible technologies without weighted records.	engineering change record, process specification, validation report, product test
dq_geography	electricity, supply chain, use, and end-of-life	State manufacturer site, grid mix geography, supplier geography where known, sale/use geography, and end-of-life route geography.	site metadata, utility contract, supplier declaration, scenario record
dq_completeness	all inventory	Screen the complete product-specific BOM and all foreground meters, chemicals, direct emissions, rejects, packaging, accessories, and conditional stages; quantify and justify exclusions.	completeness checklist cross-referenced to BOM, meters, permits, and waste register

9. Validation Rules

rule_id	Applies to	Rule	source_ids
validate_identity	product category and reference flow	Confirm the declared product is a finished worn, carried, or implantable compensatory appliance and that the reference UUID, mass property, and kg unit are unchanged.	un-cpc-3-0-2025
validate_qualifiers	foreground data package	Fail completeness when appliance subtype, intended purpose, active/passive state, worn/carried/implantable state, unit count, mass, configuration, power chemistry, sterile state, geography, service life, or boundary is missing.	eu-mdr-2017-745; ec-pef-2021
validate_bom	production inventory	Confirm every BOM component and every packaging item is represented by an atomic inventory row or a disclosed, quantified exclusion; verify that included accessories are not hidden in the reference-product mass.	ec-pef-2021; selhorst-et-al-2025-hearing-aid-lca
validate_conditions	conditional rows and processes	Confirm that battery chemistry, silicone earpiece, ABS moulding, sterilization route, use, and end-of-life rows are included only when their explicit conditions apply and that applicable rows are not omitted.	eu-mdr-2017-745; selhorst-et-al-2025-hearing-aid-lca
validate_no_double_count	electricity, purchased components, off-site services, and waste	Confirm foreground exchanges exclude burdens already embedded in linked supplier datasets and that off-site sterilization is not also represented as on-site sterilant and energy.	ec-pef-2021
validate_allocation	shared operations	Confirm subdivision was attempted first and every remaining allocation uses a recorded causal physical driver with numerator, denominator, and period.	ec-pef-2021
validate_mass_balance	assembly and end-of-life	Confirm input, conforming output, rework, reject, separately supplied accessory, packaging, and waste masses reconcile within a declared tolerance; explain any imbalance.	ec-pef-2021
validate_range_status	important inventory flows	Confirm foreground values come from the declared collection protocols. Treat external range evidence as unresolved until at least two independent, boundary-compatible original sources support a synthesized interval.	ec-pef-2021

10. Published Dataset Profile

Field	Value
dataset_role	Product-specific foreground production dataset; conditional stage datasets may be published separately and linked
downstream_use	secondary_dataset or background_dataset for a declared appliance configuration and geography; input to a lifecyclemodel only when conditional stages and reference-flow conversion are explicit
allowed_use	Modelling the named appliance subtype, BOM revision, production route, sterile state, manufacturer-gate geography, power system, and declared time period; scenario-specific use or end-of-life only where those stages are included
excluded_use	Generic use for unrepresented appliance subtypes, implantable versus non-implantable substitution, different battery chemistry, different sterile state, or comparative claims without equivalent function, service life, boundary, and data quality
required_metadata	canonical PCR id; product and reference-flow UUIDs; appliance subtype and intended purpose; active/passive and worn/carried/implantable state; unit count and net mass; BOM revision; configuration and accessories; power chemistry; sterile state and method; site and market geography; technology; reporting period; service life; boundary; allocation; cut-offs; background dataset versions
required_quality_disclosure	primary-data share; meter and mass coverage; BOM completeness; unresolved UUIDs; proxy datasets; allocation drivers; mass-balance result; temporal, technological, and geographic representativeness; excluded flows and stages; uncertainty; range-evidence gaps
update_trigger	Change in intended purpose, product subtype, BOM or accessory configuration, cell chemistry, housing material, electronic module, assembly line, sterilization route or abatement, packaging, supplier geography, grid mix, service-life claim, use scenario, end-of-life route, or evidence that materially changes inventory results

11. Data Sources

Source id	Type	Reference	Used for
un-cpc-3-0-2025	official_guidance	United Nations Statistics Division, Central Product Classification 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 2026-09-06)	Official CPC 48172 classification identity and English title
ec-pef-2021	official_guidance	European Commission, Annex I, Product Environmental Footprint Method, Commission Recommendation (EU) 2021/2279, https://environment.ec.europa.eu/system/files/2021-12/Annexes%201%20to%202.pdf (retrieved 2026-09-06)	Functional-unit structure, product-specific BOM and manufacturing data, life-cycle stages, allocation, cut-off, collection, and end-of-life modelling rules
eu-mdr-2017-745	standard	Regulation (EU) 2017/745 of the European Parliament and of the Council on medical devices, consolidated official text, https://eur-lex.europa.eu/eli/reg/2017/745/oj/eng (retrieved 2026-09-06)	Intended-purpose, implantable-device, sterile-state, sterilization-method, identification, performance, and expected-lifetime qualifiers
selhorst-et-al-2025-hearing-aid-lca	literature	Selhorst, R. da R.; Alves, C.; Li, C.; Silva, A. (2025), Life Cycle Assessment of Hearing Aid Devices: Environmental Impact Analysis and Improvement Opportunities, Recycling 10(6), 219, https://doi.org/10.3390/recycling10060219 (retrieved 2026-09-06)	Hearing-aid-specific process decomposition and primary-data methods for BOM, component mass, manufacturing energy, packaging, distribution, use consumables, and end-of-life