Guidance

Aggregate from waste steel slag: quality protocol

Updated 4 May 2016

This quality protocol applies to England, Wales and Northern Ireland.

1. When the final product is no longer waste

Aggregate product made from waste steel slag will be regarded as fully recovered and no longer subject to waste controls providing you can show that you:

• used only the correct waste steel slag materials
• made only the permitted products
• complied with the relevant European standard, specification and quality controls for the product you are making, and it passes all required tests and needs no further treatment, weathering or size reduction before use
• have a manual of your factory production control (FPC)
• have marked the product to the CE requirements of the Construction Products Regulations
• transported, stored, handled and processed the waste steel slag and the final product following good practice guidelines
• supplied the customer with delivery documents confirming the product meets the quality protocol

Always make sure you follow duty of care responsibilities, and conditions on any environmental permit or waste management licence or exemption you hold.

2. Waste you can use and codes

You must only use the slag waste from steel-making method:

• basic oxygen steelmaking (BOS)
• electric arc furnace (EAF) - including carbon steel EAF and high alloy EAF
• argon oxidisation decarburisation (AOD)

The European Waste Catalogue (EWC) codes for steel slag are:

• 10.02.01 – wastes from the iron and steel industry from slag processing
• 10.02.02 – unprocessed slag waste from the iron and steel industry

3. Uses

Under the quality protocol you can process the correct waste steel slag to make specified unbound, semi-bound or fully bound aggregate products for use in the civil engineering and construction industries.

3.1 End uses for the types of steel slag aggregates

For unbound uses (BOS and carbon steel EAF slag aggregates only) the end uses are:

• aggregates for sub-base
• capping
• fills
• pipe bedding

For semi-bound uses (BOS, carbon steel EAF and high alloy EAF aggregates only) the end use is:

• aggregates for surface dressing

For bound uses (BOS carbon steel EAF, high alloy EAF and AOD slag aggregates), the end uses are both:

• aggregates for asphalt and concrete
• aggregates and activators for hydraulically bound mixtures

The standards and specification for each product and its intended use will tell you what shape, size, weathering or other processing you need to carry out.

Note: Lime that is present in unweathered steel slag may make the aggregate liable to later expansion and unsuited to certain uses. Always check the weathering time in line with the expansion testing requirements in BS EN 1744-1, for the product you intend to make.

4. Record input waste

Whether you use on-site waste steel slag, or have waste steel slag delivered for processing, keep records of:

• whether it’s BOS, EAF or AOD waste steel slag – and include the EWC code
• its volume or weight
• the source of the waste
• the date of delivery, and name and address of the supplier and carrier if the waste is not already on site
• your method for confirming the waste is acceptable input material – if not, your rejection or quarantine reasons and what you did with the rejected waste

5. Standards, specifications and quality controls

Note that FPC is factory production control.

5.1 Standards, specifications and quality controls for the use of aggregates

Product end use: unbound steel slag aggregate - pipe bedding

Standard: BS EN 13242

Application specification: Highway Works series 500

Quality controls: evaluation of conformity to standard and specification, and FPC to Level 4 of BS EN 13242

Product end use: unbound steel slag aggregate - granular fill and general fill capping

Standard: BS EN 13242

Application specification: Highway Works series 600 and BS EN 13285

Quality controls: evaluation of conformity to standard and specification, and FPC to Level 4 of BS EN 13242

Product end use: unbound steel slag aggregate - sub base

Standard: BS EN 13242

Application specification: Highway Works series 800 and BS EN 13285

Quality controls: evaluation of conformity to standard and specification, and FPC to Level 4 of BS EN 13242

Product end use: semi-bound steel slag aggregate - surface dressing

Standard: BS EN 13043

Application specification: Highway Works series 900

Quality controls: evaluation of conformity to standard and specification, and FPC to Level 2+ BS 13043 for high safety applications, or Level 4 BS 13043 for other applications

Product end use: steel slag aggregate for concrete

Standard: BS EN 12620

Application specification: Highway Works series 1000 and BS 8500-2

Quality controls: evaluation of conformity to standard and specification, and FPC to Level 4 of BS EN 12620

Product end use: steel slag aggregate for asphalt

Standard: BS EN 13043

Application specification: Highway Works series 900

Quality controls: evaluation of conformity to standard and specification, and FPC to Level 2+ BS 13043 for high safety applications, or Level 4 BS 13043 for other applications

Product end use: steel slag aggregate for hydraulically bound mixtures

Standard: BS EN 13242

Application specification: Highway Works series 800 and BS EN 14227-1 to 5

Quality controls: evaluation of conformity to standard and specification, and FPC to Level 4 of BS EN 13242

The British Standards Institution has guidance documents explaining how to apply the European Aggregate Standards within the UK. These are:

• PD 6682-1 - for BS EN 12620
• PD 6682-2 - for BS EN 13043
• PD 6682-6 - for BS EN 13242

You can find the British Standard Institution’s engineering standards from the bsi website and the highway works series from the Department for Transport website’

6. Factory production control (FPC)

You must have FPC in place to comply with the quality protocol and the BS EN standard for the product you are making. FPC is a record of all your policies and methods for managing the waste material - from steel slag arriving on site, through to storage, processing, transport, and delivery of quality protocol approved products to your customer.

It must include:

• how you assess and record input waste, your method statement of production (MSP), processing techniques, product testing, and staff training – set out each step and result, and specify how long you keep these records
• a description of the delivery documents you give to customers
• regular reviews to ensure practices and methods are up-to-date and work properly – you must keep a record of these reviews and detail any actions or changes you make
• a policy for managing any subcontractors
• a named representative responsible for the FPC and its correct use

6.1 Method statement of production (MSP)

You need a written description of your methods for processing the waste steel slag for every product type you make. Include:

• what waste material you use, how you select it and how and where you store it
• the equipment you use and how you maintain it – record all checks and repairs or adjustments during production
• the checks you make for deterioration and product quality during handling, storage, transport and delivery
• how you identify your finished product up to the point of sale

6.2 Inspection, measuring and testing equipment

Keep method statements and records for:

• what equipment you have, with a unique identification for each
• maintenance and inspections
• how you use it, and any controls and adjustments you make

6.3 Staff training

You must train staff to understand and apply:

• waste material acceptance criteria
• procedures for dealing with non-compliant wastes
• inspections, sampling and testing

7. Tests

You must have a plan that specifies the type and frequency of testing for each aggregate product you produce from steel slag waste.

Make sure your testing programme conforms to both:

• test specifications in the BS EN standard for your aggregate product
• the test minimum frequency requirements

7.1 Testing requirements associated with particular end uses and standards

Product standard BS EN 13242

Test: particle size distribution, BS test refererence: EN 933-1, minimum test frequency: weekly

Test: fines content, BS test reference: EN 933-1, minimum test frequency: weekly

Test: particle density and water absorption, BS reference: EN 1097-6, minimum test frequency: yearly

Test: resistance to fragmentation (Los Angeles), BS reference: EN 1097-2, minimum test frequency: twice a year

Test: volume stability, BS reference: EN 1744-1, minimum test frequency: twice a year

Test: magnesium sulphate soundness, BS reference: EN 1367-2, minimum test frequency: once every 2 years

Product standard BS EN 12620

Test: particle size distribution, BS test refererence: EN 933-1, minimum test frequency: weekly

Test: fines content, BS reference: EN 933-1, minimum test frequency: weekly

Test: particle density and water absorption, BS reference: EN 1097-6, minimum test frequency: yearly

Test: resistance to fragmentation (Los Angeles), BS reference: EN 1097-2, minimum test frequency: twice a year

Test: sulfur containing compounds, BS reference: EN 1744-1, minimum test frequency: yearly

Test: magnesium sulphate soundness, BS reference: EN 1367-2, minimum test frequency: once every 2 years

Product standard BS EN 13043

Test: particle size distribution, BS reference: EN 933-1, minimum test frequency: weekly

Test: fines content, BS reference: EN 933-1, minimum test frequency: weekly

Test: particle density and water absorption, BS reference: EN 1097-6, minimum test frequency: yearly

Test: resistance to fragmentation (Los Angeles), BS reference: EN 1097-2, minimum test frequency: yearly

Test: polished stone value (surface coarse only), BS reference: EN 1097-8, minimum test frequency: yearly

Test: volume stability, BS reference: EN 1744-1, minimum test frequency: twice a year

Test: magnesium sulphate soundness, BS reference: EN 1367-2, minimum test frequency: once every 2 years

You may interpret minimum test period frequencies in 2 ways. For example, if a minimum testing frequency is weekly, you may take this as 7 consecutive days of which 5 are production days, or the time it takes to complete 5 production days.

Keep test results for the time specified in your FPC – the quality protocol minimum is 2 years. You can also create summaries, for example, as a graph of test results over time.

7.2 When to test more or less often

If you know the quality of your waste material or recycled aggregate is close to failing a standard, you should test the product more often. Record your increased test schedule in your FPC manual.

You may reduce your test frequency if:

• you are using highly automated, precision production equipment
• you have proven, long-term experience with consistency of a material’s special properties
• your waste materials have proven high conformity
• you have a quality management system with exceptional product checking

You must give a full statement with reasons for reducing test frequencies in your FPC manual.

8. Good practice

8.1 Move, store and handle waste steel slag and the final aggregate product safely

All producers, distributors and users should minimise harm from dust and airborne particles when moving, processing or using waste steel slag or its aggregate products.

Take action to keep employees safe – follow Health and Safety Executive advice and provide personal protective equipment.

Where possible, use mechanical means of moving the aggregate rather than by hand – check the manual handling regulations.

Prevent dust and fine particles entering watercourses or drains, or landing on surrounding vegetation or property. You can use:

• enclosed containers, silos, bins and hoppers
• local exhaust ventilation and spray suppression systems
• open conveyors with wind boards to limit wind whipping

When using aggregate on construction or demolition sites follow the guidance:

• Pollution Prevention Guidelines PPG6
• Construction Industry Research and Information Association’s (CIRIA’s) Environmental Good Practice on Site (C692)

9. Paperwork and records checklist

You must keep information about your waste steel slag recovery process and aggregate production methods for 2 years.

All records must be legible and available to the Environment Agency on request.

9.1 Incoming waste

Record all input waste steel slag you accept or reject for aggregate processing – you may also need this information for your permit conditions.

9.2 Production data

Keep a copy of all tests - this includes details of any test failures, and adjustments you make to your production and control methods to meet the standard or specification for your intended product.

9.3 Outgoing steel slag aggregate product

You must create a document for your customer and keep a copy for your records. Include:

• name and details of the aggregate product, including any customer specification
• producer’s name, address and contact details
• site address of production
• date of product dispatch
• quantity by volume or weight
• any identifying batch or serial number
• name, address and contact details of the customer
• description of the customer’s business
• a statement of conformity to say the product meets the quality protocol and all standards, specification and quality control checks

If the customer asks, you must also include:

• results of any product tests
• outline details of your factory production control (FPC) manual
• good practice guidance for storing, transporting and handling the product

10. Unused steel slag aggregate: loss of non-waste status

Quality protocol compliant steel slag aggregate will become waste and subject to waste management controls if at any stage you dispose of it, or store it indefinitely with little prospect of use as an approved end product.

This applies to anyone holding stores of aggregate made from waste steel slag, not just producers.

11. Reviewing this quality protocol

We will review and update this quality protocol as needed. This could be because there is a:

• pollution incident
• change in the market
• change in legislation or case law
• change in the understanding of risk of steel slag
• significant change to the processes or technologies which produce steel slag

If the composition of the steel slag exceeds any of the limits in section 9 of the steel slag technical report that slag may not qualify as an input for this quality protocol.

Email endofwaste@environment-agency.gov.uk for a copy of the report.

12. Blended steel slag aggregate

If you blend quality protocol compliant steel slag aggregate with:

• waste material, the whole mixed volume becomes waste and you must apply waste management controls
• non-waste material, the whole volume is non-waste – but you will need to check it meets the standard, specification and quality controls of the end product you want to make