Section 04 · The Dossier E-20
The Tonnage Band
How much is made decides how much has to be known about it.
The staircase of obligation
Under REACH — the European chemicals regulation that came into force in 2007 — the data required before a substance can be placed on the market scales with the volume manufactured or imported into the European Economic Area. The unit is tonnes per manufacturer per year, and the thresholds create four steps: one tonne, ten tonnes, one hundred tonnes, and one thousand tonnes.
At one tonne per year — the registration floor — the dossier is relatively lean: physicochemical properties, basic toxicological endpoints, and an initial chemical safety assessment where required. Cross the ten-tonne threshold and additional endpoints become mandatory: repeated-dose toxicity, reproductive screening, an extended safety assessment. At one hundred tonnes, the list lengthens again. At one thousand tonnes, the highest band, the full suite of long-term studies is triggered.
The logic is deliberate. Higher volumes imply wider dispersal, greater potential for environmental loading, and more occupational contact — so the justification for requiring more data is proportionality, not punitiveness. Volume is a proxy for exposure potential, and exposure potential is the regulator's first proxy for where scrutiny is warranted.
The figure that determines the band is the manufacturer's or importer's own declaration, updated whenever a tonnage threshold is crossed. If production scales up and pushes the registrant into the next band, the dossier must be updated to meet the new requirements within the prescribed transitional period. The obligation runs per legal entity, not per substance globally: two companies registering the same compound independently each report their own volume and carry their own dossier obligations.
One practical consequence appears often in the registration dossier: a data gap that would require expensive long-term study is sometimes addressed by a voluntary downward revision of reported tonnage — keeping the registrant in a lower band and out of the study trigger. Regulators are alert to this; dossier evaluations may scrutinise whether declared volumes are plausible given market evidence.
The tonnage band is therefore not merely an administrative category. It is the mechanism by which the regulation allocates evidential burden — deciding which questions must be answered before a substance is permitted on the market, and which may be deferred. When a measurement report cites a regulatory threshold or data requirement, the tonnage band is usually the reason that number, and not another, appears on the page.
Filed inSection 04 — The Dossier