Proposal to reduce frequency, increase timing window of US low-carbon aluminium differentials

Fastmarkets proposes to lower the frequency of its assessments for MB-AL-0389 aluminium low-carbon differential P1020A, US Midwest and MB-AL-0390 aluminium low-carbon differential value-added product US Midwest. Fastmarkets also proposes to extend the timing window of these same assessments to include any transaction data concluded within up to 18 months.

The first proposed amendment would decrease the differentials’ publishing frequency to once monthly from once weekly. The monthly frequency matches Fastmarkets’ low-carbon aluminium differentials in other regions and better reflects current market liquidity.

The second proposed amendment would extend the timing window to include any transaction data concluded within up to 18 months from three months previously. The extension of the timing window will allow for an inclusive approach to an evolving low-carbon marketplace, allowing Fastmarkets to capture all reported transaction data under one robust differential.

The new proposed specifications for the premium will be as follows (changes in italics):

MB-AL-0389 Aluminium low-carbon differential P1020A, US Midwest, US cents/lb
Carbon limit: 4tCO2e per tonne of aluminium produced, Scope 1 and 2 emissions.
Quality: P1020A or 99.7% minimum Al purity (Si 0.10% max, Fe 0.20% max). Ingot,
T-bar, sow
Quantity: Min 100 tonnes
Location: Delivered consumer works Midwest, differential on top of P1020A premium and exchange-listed aluminum price
Unit: US cents per lb
Timing: Up to 18 months
Publication: Monthly, first Friday of the month, 3-4pm London time

MB-AL-0390 Aluminium low-carbon differential value-added product, US Midwest, US cents/lb
Carbon limit: 4tCO2e per tonne of aluminium produced, Scope 1 and 2 emissions.
Type: Extrusion billet, primary foundry alloy, wire rod, slab
Quantity: Min 100 tonnes
Location: Delivered into US Midwest region, differential on top of value-added product premium and exchange-listed aluminum price
Unit: US cents per lb
Timing: Up to 18 months
Publication: Monthly, first Friday of the month, 3-4pm London time

The consultation period for these proposed changes starts from Thursday November 21 and will end on Monday December 23, with an update published on that day. The assessments scheduled for Friday December 27 would then be skipped, with the first monthly assessments taking place on Friday January 3, subject to market feedback.

To provide feedback on this price, or if you would like to provide price information by becoming a data submitter to this price, please contact Yasemin Esmen by email at pricing@fastmarkets.com. Please add the subject heading “FAO: Yasemin Esmen, re: US low-carbon aluminium differentials.”

Please indicate if comments are confidential. Fastmarkets will consider all comments received and will make comments not marked as confidential available upon request.

To see all Fastmarkets pricing methodology and specification documents, go to https://www.fastmarkets.com/methodology.

What to read next
Fastmarkets has corrected the rationale for its MB-CO-0005 Cobalt standard grade, in-whs Rotterdam, $/lb price assessment, which was published incorrectly on Monday March 23 due to a typo.
Fastmarkets has suspended three price assessments, and changed the incoterm for two price assessments that were previously on a cfr Jebel Ali basis, to take effect from March 24, 2026. This follows the escalation of the conflict between the US, Israel and Iran, and consequent disruptions to deliveries in the region. The following prices are […]
Fastmarkets proposes to discontinue daily price assessments for Rapemeal FOB ARAG RMP € per mt, Sunoil CPT Ukraine Danube $ per mt; Corn FOB Ukraine Handy $ per mt; and Corn FOB Ukraine Handy Premium c$ per bu.
Fastmarkets discontinued its weekly price assessments for AG-TLW-0028 Category 3 bone fat, high grade, 5% ffa, 98%, max 200 ppm polyethylene, ddp Northwest Europe and AG-TLW-0029 Category 3 pure beef tallow, 10% ffa, 99%, ddp Northwest Europe on Friday March 20.
Fastmarkets has corrected its copper concentrates treatment and refinement charge indices, which were published incorrectly on March 20 2026 due to a technical error.
Fastmarkets launched three new rare earth prices on Thursday March 19 to cover the global market outside of China to improve transparency in the rare earths magnet supply chain.