Guidance

Ferrous and non-ferrous metals: pollution inventory reporting

Updated 29 November 2024

Applies to England

• Publication for Northern Ireland
• Publication for Scotland
• Publication for Wales

If you operate an A1 facility, you will need to submit data to the pollution inventory.

The ‘general guidance’ available in the pollution inventory reporting guidance gives information that applies to all business and industries. It explains what the pollution inventory is and how to report.

This guidance gives information specific to ferrous and non-ferrous metals activities.

If your operations include waste incineration or combustion, you may also find the guidance for those sectors useful.

Emissions to air

Relevant pollutants

This page lists the main air emissions from ferrous and non-ferrous metals production and processing activities.

These lists are only a guide - you must check that there are no other pollutants emitted from your process.

At the end of this page there is:

• a summary of currently used release emission techniques (RETs)
• guidance for releases of substances to air from various sources

Ferrous metal activities

The most common air pollutants emitted by ferrous metal and related activities, and their main sources, are:

• ammonia (NH₃), from coke oven charging emissions and door leakage
• benzene, toluene and xylene (BTX) from coke oven door leakage, emergency venting, and decanters and storage tank vents
• carbon dioxide (CO₂), from sinter plant, hot blast stoves, blast furnaces, BOS blowing and charging operations, arc furnace melting and refining, arc furnace and ladle treatment scarfing, and coke ovens re-heating
• carbon monoxide (CO), from sinter plant, hot blast stoves, blast furnaces, BOS blowing and charging operations, arc furnace melting and refining, scarfing, emergency venting, and re-heat furnaces
• dioxins and furans, from sinter plant, and arc furnace steel making
• fluorine and inorganic compounds (as HF), from sinter plant, arc furnace melting and refining, ladle treatments, and electro slag remelting
• hydrochloric acid/hydrogen chloride (HCl), from sinter plant, and hydrochloric acid pickling
• hydrogen cyanide (HCN), from coke oven charging, and door and top leakage
• metals, from sinter plant, BOS charging and tapping operations, arc furnace charging, and melting and refining
• methane (CH₄), from sinter plant, and coke oven door leakage
• nitrogen oxides (NOx), from sinter plant, hot blast stoves, arc furnace charging, melting and refining, nitric acid pickling, coke oven under-firing, emergency flaring, and ammonia incinerator tail gas
• particulate matter (including PM2.5 and PM10), from raw material handling, sinter plant, coal pulverisation, stockpiles, blast furnaces, desulfurisation plant, BOS/electric arc primary and secondary extraction charging and tapping operations, ingot casting, scarfing, skull burning, coke oven door leakage/under-firing/charging/pushing, emergency venting, emergency flaring, and quenching ammonia incinerator tail gas
• phenols, from coke oven door and top leakage, emergency venting, decanters and storage tank vents, and coke oven by-product plant
• poly aromatic hydrocarbons (PAHs), from sinter plant, electric arc furnace steel making, and coke oven door and top leakage (reference to PAHs is for collective convenience - see the pollution inventory reporting form for your industry for which PAH you should report)
• poly chlorinated biphenyls (PCBs), from sinter plant, and electric arc furnace steel making
• sulfur dioxide (SO₂), from sinter plant, hot blast stoves, arc furnace charging, melting and refining, slag processing, coke oven under-firing, ammonia incinerator tail gas, blast furnace cast house extraction, and re-heating
• volatile organic compounds (VOCs), from sinter plant, coke oven charging emissions, door leakage and by-products plant, decanters and storage tank vents

Non-ferrous metal activities

The most common air pollutants emitted by non-ferrous metal and related activities, and their main sources, are:

• ammonia (NH₃), from aluminium, precious metal, and refractory metal processes
• carbon dioxide (CO₂), from melting furnaces
• carbon monoxide (CO), from shaft furnaces in copper processes, and nickel and cobalt processes
• chlorine and inorganic compounds (as HCl), from aluminium, lead, zinc, cadmium, precious metal, refractory metal, and alkali and alkaline metal processes
• dioxins and furans, from pre-treatment (copper, aluminium, lead, zinc, cadmium, precious metal, refractory metal, ferro alloy, alkali and alkaline metal, and nickel and cobalt processes), carbon and graphite production, residue handling storage and re-use, and air abatement plant
• fluorine and inorganic compounds (as HF), from aluminium and precious metal processes, and pickling
• dioxins and furans, from pre-treatment (copper, aluminium, lead, zinc, cadmium, precious metal, refractory metal, ferro alloy, alkali and alkaline metal, and nickel and cobalt processes), carbon and graphite production, residue handling storage and re-use, and air abatement plant
• hydrochloric acid/hydrogen chloride (HCl), from aluminium and precious metal processes, and pickling
• nitrogen oxies (NOx), from pre-treatment (copper, aluminium, lead, zinc, cadmium, precious metal, refractory metal, ferro alloy, alkali and alkaline metal, and nickel and cobalt processes), and carbon and graphite production
• non-ferrous metals, from raw material storage and handling, pre-treatment (copper, aluminium, lead, zinc, cadmium, precious metal, refractory metal, ferro alloy, alkali and alkaline metal, and nickel and cobalt processes), carbon and graphite production, residue handling storage and re-use, and air abatement plant
• perfluorocarbons (PFCs), from aluminium processes
• poly aromatic hydrocarbons (PAHs), from aluminium processes, and carbon and graphite production (reference to PAHs is for collective convenience - see the pollution inventory schedule for which PAHs should be reported)
• sulfur dioxide (SO₂), from pre-treatment (copper, aluminium, lead, zinc, cadmium, precious metal, refractory metal, ferro alloy, alkali and alkaline metal, and nickel and cobalt processes), and carbon and graphite production
• total particulate matter (including PM2.5 and PM10 as a % of total), from raw material storage and handling (pre-treatment; copper, aluminium, lead, zinc, cadmium, precious metal, refractory metal, ferro alloy, alkali and alkaline metal, and nickel and cobalt processes), carbon and graphite production, residue handling storage and re-use, and air abatement plant
• volatile organic compounds (VOCs), from pre-treatment (copper, aluminium, lead, zinc, cadmium, precious metal, refractory metal, ferro alloy, alkali and alkaline metal, and nickel and cobalt processes), carbon and graphite production, and air abatement plant

Emission sources

Point source emissions

These emissions are exhausted via a stack or vent. That is, a single point source into the atmosphere. Abatement equipment, for example scrubbing units, fabric filters (bag house) can be incorporated into the exhaust system prior to discharge to atmosphere.

Point source emissions will be the most significant emission source for combustion activities taking place within metals processing and production sites. Other non-combustion point source emissions (sintering, coke making, smelting, refining, alloying, and so on) arise from a wide range of ferrous and non-ferrous processes and activities.

Fugitive emissions

Fugitive emissions are those that are not released from a point source such as a stack. Only fugitive emissions that leave the site need to be reported to the pollution inventory. Contained spills do not need to be reported but you should report vapour emissions that may have dispersed. Any spills may still need to be reported in other ways as part of your permit conditions.

Fugitive emissions from coke, and iron and steel processes can be as significant as point source emissions. Some examples are:

• leakage of volatile materials through ascension pipes, door seals, and lid seals on coke ovens
• open vessels (for example, coke oven by-product plant)
• cast house fume abatement systems overloaded
• BOS primary and secondary fume collection
• coal and ore stockpiles
• vehicle loading and unloading areas
• transferring material between vessels (for example, furnace, ladle, silos)
• conveyor systems
• pipework and ductwork systems (for example, pumps, valves, flanges)
• abatement equipment by-pass (for example, coke side particulate collection hoods)
• accidental loss of containment from failed plant and equipment
• solvents
• miscellaneous unextracted combustion activities

At most sites where non-ferrous metals processes are carried out, fugitive emissions to air give rise to a significant proportion of the overall environmental impact. Some examples are:

• smelting, melting and refining furnaces, and their associated extraction systems
• transfer operations involving molten metal
• casting and associated activities
• handling and storage of dusty raw materials such as concentrates, foundry sand, and drosses
• handling, storage, and disposal of wastes such as drosses, slags and skimmings
• fume treatment plant
• ladle heating stations
• vehicle loading and unloading areas

Fuel analysis, process stream data and normalisation

The use of fuel analysis and process stream data to determine emissions is similar to the use of emission factors.

Check the ‘technical guidance and equations’ in the pollution inventory reporting: guidance notes for:

• equations and an example
• formulae for conversion between normalised and actual emission concentrations

Take care, in all calculations, to ensure that the emission concentration and flow rate are compatible. For example, you should multiply:

• normalised emission concentrations by normalised volumetric flow rates
• actual measured emission concentrations by actual measured volumetric flow rates

Many ferrous and non-ferrous processes are carried out as batch processes. For example, anode baking in the primary aluminium industry. Data should be generated using measurements taken over the entire period of the batch production process to ensure representative (total mass) data are obtained.

Emissions to water

Emissions of substances to water can be either direct to controlled waters or indirect, following transfer to off-site effluent treatment plant.

Check the ‘general guidance’ in the pollution inventory reporting: guidance notes for what constitutes an emission or a transfer.

We recognise that you may experience difficulty disaggregating EPR and non-EPR releases of substances to water where both pass through a common monitoring point as a combined effluent. Use the combined effluent value where it is not possible to estimate the individual contributions.

Relevant pollutants and emission sources

Water discharges from ferrous and non-ferrous metals processes can be contaminated by a variety of polluting substances.

We have provided lists to illustrate the most common substances emitted to water and their main sources. Use these as a guide only, and check that there are no other pollutants emitted from your processes. Suspended solids, and oils and greases, are not pollution inventory reportable substances, but you may need to take account of other substances that are being emitted in association with such materials.

See currently used RETs and guidance for releases of substances to water from various sources at the end of this guidance.

The most common water pollutants generated by ferrous metal and related activities, and their sources, are:

• ammonia (NH₃), from blast furnace primary gas cleaning, effluent plant, and coke oven by-products
• cyanides (as CN), from blast furnace primary gas cleaning, effluent plant, and coke oven by-products
• metals, from effluent treatment discharge
• oils and greases, from steel scrap storage and handling, residue handling, storage and re-use, continuous casting, and rolling mills
• poly aromatic hydrocarbons (PAHs), from coke oven by-products
• suspended solids, from raw material storage and handling, residue handling, storage and re-use, effluent plant, blast furnace and BOS gas cleaning, and rolling mills
• total organic carbon (TOC), from steel scrap storage and handling, residue handling, storage and re-use, continuous casting, rolling mills, and by-products plant

The most common water pollutants generated by non-ferrous metal and related activities, and their sources, are:

• ammonia (NH₃), from blast furnace primary gas cleaning, effluent plant, and coke oven by-products
• cadmium (Cd), from raw material storage and handling, and effluent plant
• cyanides (as CN), from blast furnace primary gas cleaning, effluent plant, coke oven by-products
• mercury (Hg), from raw material storage and handling, and effluent plant
• oils and greases, from steel scrap storage and handling, residue handling, storage and re-use, continuous casting, and rolling mills
• other metals, from effluent treatment discharge
• poly aromatic hydrocarbons (PAHs), from coke oven by-products
• perfluorocarbons (PFCs), from aluminium processes
• suspended solids, from raw material storage and handling, residue handling, storage and re-use, effluent plant, blast furnace and BOS gas cleaning, and rolling mills

The resulting discharges of the above substances depend on the ‘in process’ preventative measures (good housekeeping, re-use, and so on) and the presence and technical standards of wastewater treatment facilities.

Off-site transfers

Relevant wastes

You must classify wastes using the European Waste Catalogue 6-digit codes and the relevant Waste Framework Directive disposal or recovery codes. Check the ‘reporting codes list’ in the pollution inventory reporting: guidance notes.

Integrated steelworks

The management of residues in an integrated steelworks is characterised by advanced techniques for extracting value from recycling most of the residues in the sinter plant, BOS plant and coke ovens. The iron and steel sector is an important recycler of materials. All the ferrous scrap arisings in the UK are recycled, the bulk of it by the UK steel industry. Only small parts of the overall quantity of wastes are landfilled, including the following:

• fine dust from blast furnace gas cleaning
• rubble
• fine dust from basic oxygen furnace gas scrubbing (where wet cleaning is used)
• alkali metal chlorides and heavy metal chlorides from electrostatic precipitators
• refractory waste
• general, for example, packaging

Hot and cold rolling mills

Hot rolling operations generate the following waste products which are sent off site:

• metal bearing wastes (for example, oily mill scale)
• dusts from scarfing and rolling
• oily and non-oily mill scale
• water treatment and mill scale sludge
• oil and greases (can be used as secondary fuel in blast furnace or coke ovens)

Cold rolling operations generate the following waste products which are sent off site:

• acid neutralisation sludges
• oily sludges

Non-ferrous metal processes

The production of non-ferrous metals from primary and secondary raw materials gives rise to the generation of a wide variety of by-products, intermediate products, and residues. For example:

• tars or carbon-containing wastes from anode manufacture
• flue gas dust
• gas treatment sludges
• lining and refractory waste
• wastewater treatment sludge
• waste oils
• absorbents and filter materials

Quantification of emissions

Do not report wastes that are temporarily stored on site by yourself. You do need to report waste transferred to third parties (even if stored on your site).

Transboundary shipments of hazardous waste

You must report the annual quantities of any transboundary hazardous waste shipments taking place to the pollution inventory.

Release emission techniques

These sections have extra information about emissions from ferrous and non-ferrous metals processes. We cover the main categories of emission sources:

• process emissions (including integrated iron and steel processes, coke making and rolling mills)
• combustion emissions (heaters, boilers, and so on)
• fugitive emissions
• wastewater

We have listed the pollutants we consider potentially emitted from typical metal processes and included emission factors where available. For pollutants not listed, we generally expect a return of not applicable (n/a) to indicate that this pollutant is not knowingly discharged by the site. You should use your own judgement and knowledge and report any substance emitted, even if it is not on the list.

Ferrous metals source factors

The letter C or M tells you if we expect this to be calculated or measured.

Emissions to air

The main emissions to air are:

• ammonia (NH₃) - C from 1° and 2° rolling mills
• ammonia (NH₃) - C or M from coke oven charging, coke oven door leakage, and coke oven pushing
• benzene - C from coke making
• cadmium (Cd) - C from 1° and 2° rolling mills
• cadmium (Cd) - C or M from coke making, blast furnace, and combustion
• cadmium (Cd) - M from sinter plant and steel making
• carbon dioxide (CO₂) - C from site combustion and process sources – refer to guidance from the UK Emission Trading Scheme (UK ETS)
• carbon monoxide (CO) - C from BOS refining, EAF steel making, and 1° and 2° rolling mills
• carbon monoxide (CO) - C or M from combustion, coke oven charging and door leakage, coke oven pushing, and sinter plant wind box
• dioxins and furans - M from sinter plant and EAF steel making
• fluorine and inorganic compounds, as HF - C or M from sinter plant and EAF steel making
• hydrochloric acid/hydrogen chloride (HCl) - C or M from combustion, sinter plant, and acid pickling
• hydrogen cyanide (HCN) - C or M from coke making
• hydrogen sulfide (H₂S) - C or M from coke making – this is stated on pollution inventory list of pollutants, but reportable as ‘Other individual acid forming gases’
• methane (CH₄) - C from combustion and coke making
• non-methane volatile organic compounds (NMVOCs) – C or M from coke oven charging, coke oven door leakage, coke oven pushing, and sinter plant
• nitrogen oxides (NOx) – C from combustion (you might have agreed site-specific factors with the EA), EAF steel making, and 1° and 2° rolling mills
• nitrogen oxides (NOx) – C or M from coke oven charging, coke oven door leakage, sinter plant, and blast furnace
• nitrous oxide (N₂O) – C from combustion
• poly aromatic hydrocarbons (PAHs) – C from combustion
• poly aromatic hydrocarbons (PAHs) – C or M from coke making, sinter plant, and blast furnace
• poly chlorinated biphenyls (PCBs) as WHO TEQ – M from EA steel making and sinter plant
• phenol – C or M from coke making and sinter plant
• total particulate matter – C from combustion
• PM10 and PM2.5 – C from combustion, blast furnace slips, blast furnace cast house and tap hole/through, hot metal desulfurisation, BOS refining, BOS charging, BOS tapping, BOS hot metal transfer, EAF steel making, steel teeming, steel casting, and 1° and 2° rolling mills
• PM10 and PM2.5 – C or M from coke oven charging, coke oven door leakage, coke oven pushing, coke oven flue gas, sinter plant wind box, sinter plant waste gas discharge
• sulfur oxides (SOx) – C from combustion (use fuel sulfur content multiplied by flow rate), sinter plant, and blast furnace
• sulfur oxides (SOx) – C or M from coke oven charging, and coke oven flue gas
• toluene – C or M from coke making, sinter plant, and blast furnace
• xylene – C or M from coke making, sinter plant, blast furnace, and sinter plant
• zinc (Zn) – C or M from sinter plant

Other metals you might release are antimony (Sb), arsenic (As), copper (Cu), chromium (Cr), lead (Pb), manganese (Mn), and nickel (Ni). You should quantify these releases by measurement.

Releases to controlled waters and transfers in wastewater

Wherever possible data should be net of incoming cooling water quality. Where this would result in a negative return (that is, removal of pollutants from incoming waters), you should record ‘n/a’, unless you have agreed something else with us.

All releases to controlled waters should be measured. We expect the emissions source will be effluent treatment facilities. You should use effluent quality data where available.

The main substances released to water are:

• ammonia (NH₃)
• arsenic (As)
• cadmium (Cd)
• chlorides (as total Cl)
• chromium (Cr)
• copper (Cu)
• cyanides (as total CN)
• fluorides (as total F)
• lead (Pb)
• mercury (Hg)
• nickel (Ni)
• PAHs - benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, indeno(123-cd)pyrene
• phenols (as C)
• total organic carbon (TOC)
• zinc (Zn)

Non-ferrous metals source factors

The letter C or M tells you if we expect this to be calculated or measured. Where no specific emission source is given, this substance can be emitted from many parts of your processes.

Emissions to air

• ammonia (NH₃) – M
• benzene – C or M
• carbon dioxide (CO₂) – C from site combustion processes – refer to guidance from the UK Emission Trading Scheme (UK ETS)
• carbon monoxide (CO) – M from combustion
• chlorine and inorganic compounds, as Cl – C or M
• dioxins and furans – M from process
• fluorine and inorganic compounds, as HF – C from primary aluminium alumina reduction
• hydrochloric acid (HCl) - M
• hydrofluorocarbons (HFCs) – C or M
• lead (Pb) – C from primary lead ore crushing, primary lead ore screening, primary lead tetrahedrite dryer, primary lead sinter machine, primary lead sinter building fugitives, primary lead blast furnace, secondary lead sweating, secondary lead reverberatory smelting, secondary lead blast smelting cupola, secondary lead kettle refining, secondary lead casting, secondary lead smelting, secondary lead kettle refining, secondary lead casting, and secondary lead sweating
• lead (Pb) – C or M from secondary copper reverberatory furnace
• mercury (Hg) - M
• methane (CH₄) – C from combustion non-methane volatile organic compounds (NMVOCs) - M
• nitrogen oxides (NOx) – C from combustion (you might have agreed site-specific factors with the EA)
• nitrous oxide N₂O – C from combustion
• perfluorocarbons (PFCs) – C or M
• phenol – C from primary aluminium alumina reduction
• PM10 – C from:
  • combustion
  • primary copper concentrate dryer followed by electric furnace and converter
  • primary copper concentrate dryer followed by flash furnace, cleaning furnace and converter
  • primary copper concentrate dryer followed by noranda reactors and converter
  • primary copper fluid bed roaster followed by electric furnace and converter
  • primary copper fluid bed roaster followed by reverberatory furnace and converter
  • primary copper fugitive emissions
  • primary copper multiple hearth roaster followed reverberatory furnace and converter
  • primary copper reverberatory furnace followed by converter
  • primary lead blast furnace
  • primary lead ore crushing
  • primary lead ore screening
  • primary lead sinter machine
  • primary lead sinter building fugitives
  • primary lead tetrahedrite dryer
  • primary zinc electric retort
  • primary zinc electrolytic process
  • primary zinc roasting
  • primary zinc sinter plant
  • primary zinc vertical retort
  • secondary copper crucible and pot furnace
  • secondary copper cupola
  • secondary copper electric arc furnace
  • secondary copper electric induction
  • secondary copper reverberatory furnace
  • secondary copper rotary furnace
  • secondary lead blast smelting cupola
  • secondary lead casting
  • secondary lead fugitive emissions
  • secondary lead kettle oxidation
  • secondary lead kettle refining
  • secondary lead reverberatory smelting
  • secondary lead sweating
  • secondary magnesium pot furnace
  • secondary zinc calcining
  • secondary zinc electric resistance sweating
  • secondary zinc fugitive emissions
  • secondary zinc kettle pot
  • secondary zinc kettle sweating
  • secondary zinc muffle sweating
  • secondary zinc muffle distillation or oxidation
  • secondary zinc retort and muffle distillation
  • secondary zinc retort distillation or oxidation
  • secondary zinc reverberatory
  • secondary zinc retort reduction
  • secondary zinc rotary sweating
  • sweating
• poly aromatic hydrocarbons (PAHs) – C from combustion, and primary aluminium alumina reduction
• sulfur oxides (SOx) – C from:
  • combustion (use fuel sulfur content multiplied by flow rate)
  • flare (use flared gas sulfur content multiplied by flow rate)
  • primary copper concentrate dryer followed by electric furnace and converter
  • primary copper concentrate dryer followed by flash furnace, cleaning furnace and converter
  • primary copper concentrate dryer followed by Noranda reactors and converter
  • primary copper fluid bed roaster followed by electric furnace and converter
  • primary copper fluid bed roaster followed by reverberatory furnace and converter
  • primary copper fugitive emissions
  • primary copper multiple hearth roaster followed reverberatory furnace and converter
  • primary copper reverberatory furnace followed by converter
  • primary lead blast furnace
  • primary lead sinter machine
  • secondary lead blast smelting cupola
  • secondary lead reverberatory smelting
• toluene – C or M
• total particulate matter – C from combustion, primary aluminium anode production, primary aluminium alumina reduction prebake cell, secondary aluminium sweating furnace, secondary aluminium smelting (crucible furnace), secondary aluminium smelting (reverberatory furnace), secondary aluminium chlorine demagging, and secondary aluminium refining
• trichloroethylene – C or M
• xylene – C or M

Other metals you might release are antimony (Sb), arsenic (As), cadmium (Cd), copper (Cu), chromium (Cr), manganese (Mn), nickel (Ni), and zinc (Zn). You should quantify these releases by measurement.

Releases to controlled waters and transfers in wastewater

Wherever possible data should be net of incoming cooling water quality. Where this would result in a negative return (that is, removal of pollutants from incoming waters), you should record ‘n/a’, unless you have agreed something else with us.

All releases to controlled waters should be measured. We expect the emissions source will be effluent treatment facilities. You should use effluent quality data where available.

The main substances released to water are:

• ammonia (NH₃)
• cadmium (Cd)
• chlorides (as total Cl)
• cyanides (as total CN)
• fluorides (as total F)
• mercury (Hg)
• PAHs - benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, indeno(123-cd)pyrene
• total organic carbon (TOC)
• zinc (Zn)