MATERIAL AUTHORISATION AND END-OF-WASTE RULES

Governments can establish or revise the legal conditions under which materials used in CDR may be supplied and used, including the point at which a recovered waste becomes a product. The lever can cover biochar sold as a soil improver, mineral residues used for enhanced weathering, and recovered aggregates used to store atmospheric or biogenic CO₂. Authorities specify acceptable inputs, treatment, product quality and intended uses so producers and customers have a repeatable route to lawful transactions. Where an existing product or waste regime can accommodate the material, it should be adapted. The intervention determines substantive eligibility; environmental labels communicate attributes, while permitting reforms organise how applications are processed. Material approval alone neither certifies a removal nor requires anyone to buy one.

Rules should distinguish a deliberately manufactured product, a production residue that qualifies as a by-product, and waste that must undergo recovery before it can lose waste status. These routes require different evidence. Authorities need to define which source materials, treatment processes and final uses are covered, and which changes require reassessment. A material safe inside concrete may be unsuitable for unrestricted spreading on land. Relevant conditions can include contaminant limits, dust and leaching tests, chemical registration, application rates and factory quality control. Product acceptance must also fit the rules governing the receiving farm or construction project. The EU fertilising-products rules, for example, distinguish market access for compliant products from lawful national restrictions on their use. Removal accounting must separately establish carbon origin, net removal and storage duration.

A published route can replace repeated arguments over whether each producer's output is a usable product or regulated waste. Suppliers can design production and testing around known requirements, and farmers or manufacturers can accept compliant material without assuming an undefined waste-management burden. Authorising a suitable residue for a specific use can expand the feedstock available to a removal method and allow material sales to accompany carbon revenue. Shared criteria also allow new suppliers to compete on compliance rather than their ability to obtain an exceptional decision. These gains depend on actual material quality and customers finding the product useful.

Removing waste controls before replacement safeguards work can turn farms or construction sites into destinations for contaminated material. A carbon-storage claim can also distract from pollutants, excessive application or unsuitable final uses. Fixed lists may exclude a safer new process, while loosely defined categories can admit materially different feedstocks without fresh assessment. Costly testing and proprietary specifications can favour established suppliers. Conflicting waste, chemical and product decisions can leave a material lawful to market but unusable at its intended destination. Authorities should also anticipate what happens to stock already sold if an approval is withdrawn, and who pays for recall, remediation or disposal. A temporary promise not to enforce a rule should not be represented as permanent product authorisation.

Authorities should assess whether the rules lead to compliant materials being supplied and used, rather than merely increasing the number of approved categories. Useful evidence includes the time and cost of resolving material status, repeat purchases, batches rejected, contamination incidents, disputed interpretations and the availability of accredited testing. Records should connect source material, treatment, batch and destination closely enough to investigate a problem or withdraw affected supply. Evaluation should distinguish product tonnage from verified net removals. Repeated failures, new evidence about exposure, or applications that do not fit the approved use should trigger revised conditions; persistent uncertainty for otherwise comparable products should trigger clearer categories or guidance.

Waste, agricultural, chemical-safety and construction authorities should determine how their respective decisions fit together and identify which body can resolve conflicting interpretations. Producers and waste holders can supply composition, process and variability data; independent laboratories and technical experts should test the proposed thresholds and sampling plans. Farmers, material purchasers and construction professionals can explain the intended use and the evidence they need before accepting a product. Workers, affected residents, land managers and environmental organisations should help identify exposure and misuse risks that product testing alone may miss. Carbon-certification bodies should align necessary records while maintaining a separate judgement about whether a removal has occurred.

Supranational authorities can create common material categories and market-access conditions, as the EU does for fertilising products. National governments can amend product, chemical and waste rules and assign assessment and enforcement duties. Regional or state governments can do the same within devolved environmental or product powers; Northern Ireland's end-of-waste arrangements include regional determinations and recognition of shared protocols. The authority controlling waste status should coordinate with the authority regulating the intended use, since one approval may not settle both questions.