A3090 Basel waste code Tannery scraps holding chrome or pesticide.

Is Basel A3090 hazardous waste?

Normally yes. A3090 is on Basel List A, so the material is presumed hazardous unless the evidence shows it has no Annex III hazardous characteristic. The exact description and any stated exclusions still have to match.

For international shipments under the federal rules, the applicant enters the waste classification in the waste-line details of the federal notification in CNMTS. The movement rules and exclusions still apply.

Is leather residue with hexavalent chromium or biocides Basel A3090 or another code?

Pick the entry whose description and conditions match the material. The code names the waste, but SOR/2021-25 scope, exclusions, destination-country controls and the intended operation are separate decisions.