The Environment Agency is calling for evidence for a new draft quality protocol (QP) for the production and use of steel slag aggregates in construction in England and Wales.

Open until 30 April, the consultation on the protocol seeks to define when aggregates from steel slags arising from steel manufacture in electric arc furnace steelmaking, basic oxygen steelmaking, and argon oxidisation decarburisation steelmaking, cease to be classed as waste and are instead deemed to be ‘fully recovered’.

It is thought that by clearly defining when this material is no longer classed as waste (which thus doesn’t have to comply with stringent waste management controls), businesses could save £6.5 million a year.

The QP draft has been put together by the Environment Agency (EA), the Waste & Resources Action Programme, (WRAP), National Resources Wales, and representatives from the construction industry.

The consultation is open to anyone, but is largely directed to those in the construction and steel slag industry.

Consultation details

Presently, slag is created during the steel process and is classified as waste. However, it is sometimes used as an aggregate on construction sites, and in this capacity EA argues that 'in certain applications [steel slag aggregate] may outperform the alternative aggregates it replaces'.

In order to adhere to the drafted QP, the slag must meet certain criteria, including:

• it has undergone separation from the molten steel through control of the slag chemistry;
• it has been processed (de-metalled), crushed, screened and size-sorted;
• it conforms to the requirements of the European standard appropriate to the use it is destined for;
• the steel slag aggregate is produced under Factory Production Control as required by the European Standard;
• it requires no further processing, including size reduction, for the use it is destined for;
• it conforms with CE conformity marking requirements contained in the Construction Products Regulations, which apply to all aggregates placed on the market to harmonised European Aggregates Standards from July 2013; and
• it is accompanied by documentation marking the product as complying with the quality protocol and therefore waste legislation no longer applies.

Questions asked in the consultation centre on whether there are any other applications of steel slag that should be considered in the QP and whether the criteria set out is stringent enough.

EA Environment & Business Manager Roger Hoare, said: "The launch of [this] consultation is good news for businesses operating in or with steel slag processors and we are keen to hear all comments and feedback on the proposals.

"If agreed, we believe the quality protocol will help reinforce and increase business activity in the steel slag market whilst also offsetting the environmental impacts caused through the mining of virgin materials.

"The Quality Protocol will undoubtedly strengthen steel slag’s position in the market as an aggregate and will help producers by giving greater clarity around the point at which it has been fully recovered and when waste controls no longer apply."

Dr Nizar Ghazireh, Senior Manager from Lafarge Tarmac, and member of the Technical Advisory Group for the steel slag Quality Protocol, added: "After eight years working together with the EA and WRAP, it is rewarding to see that the draft quality protocol has now been released for consultation."

It is expected that the quality protocol will be published ‘later this year’.

Read more about QPs in the waste sector.