The STF plenary issued its judgment on 27 May 2021 in ADI 5.995. By a 10–1 majority, the court upheld the provisions of Rio de Janeiro Law 7.814/2017 prohibiting animal use in cosmetic and related product development, experimentation, and testing within the state. By a 6–5 majority, the court declared unconstitutional the provisions restricting sale of animal-tested products from other Brazilian states and requiring “no animal testing” labelling declarations. The decision confirmed that Rio de Janeiro authorities may enforce the testing prohibition against laboratories and companies conducting cosmetic development and testing within the state, while manufacturers and distributors from other states may continue to sell animal-tested products in Rio de Janeiro. Subsequent legal analyses published through 2025 treat the 2021 ruling as settled precedent confirming state competence over testing prohibitions and federal competence over interstate commerce and labelling. Federal Law No. 15.183/2025 (effective 31 July 2025) subsequently enacted a national ban on animal testing for cosmetic ingredients and products and addressed labelling at the federal level, building on the constitutional framework established by the 2020 Amazonas and 2021 Rio de Janeiro rulings.

Anticipated Effects

If implemented as written and enforced by Rio de Janeiro state authorities, Law 7.814/2017 as upheld would require facilities in Rio de Janeiro that use animals for cosmetic and related product development and testing to cease those activities or relocate testing to jurisdictions without equivalent bans.

The invalidation of commercialisation and labelling provisions means manufacturers testing animals in other Brazilian states or abroad may continue to sell those products in Rio de Janeiro, limiting the ruling’s effect on product availability and consumer information in the state market.

If the STF’s constitutional demarcation between state testing competence and federal commerce/labelling competence continues to be applied consistently, Brazilian states may enact and enforce further cosmetic testing bans without federal constitutional challenge, while labelling and import/sales restrictions would require federal-level action — which was provided by federal Law No. 15.183/2025.

Significance Rationale

Assigned Reduces Exploitation (impact direction) because the STF confirmed the enforceability of Rio de Janeiro’s prohibition on using animals for development, experimentation, and testing of cosmetics, personal hygiene products, perfumes, and cleaning products within that state. The commercialisation and labelling provisions being struck does not reverse or diminish the testing prohibition itself.

Assigned Alters Legal Basis (impact type) because the primary mechanism is the STF’s constitutional ruling — confirming the legal basis for the state testing prohibition while simultaneously striking the commercialisation and labelling provisions as beyond state competence. The decision both affirms and delimits the legal framework for cosmetic animal testing prohibition at state level.

Assigned Moderate significance because the decision directly concerns one Brazilian state and one sector (cosmetics and personal care testing). No quantified animal number changes are documented in available sources. However, the ruling is the first STF decision to draw the constitutional line between state competence (testing) and federal competence (interstate commerce, labelling), a distinction directly applied in subsequent federal legislation. This constitutional demarcation gives the ruling broader structural significance than the Amazonas ruling, though both are Moderate within SE’s operational framework — one state, one sector, no documented system-level scale change.

The duration and persistence of the scale change in cosmetic animal testing in Rio de Janeiro is not established in available sources; no quantitative data on animal testing volumes before or after Law 7.814/2017 or the 2021 ruling are reported in sources consulted.