Aquatic and Terrestrial Ecotoxicity of Uncured Photoresin Constituents and Mixtures: Exposure Realism and Evidence Gaps

Version 0.2 supersedes ER-278 v0.1 dated 23 September 2026 and closes citation/source-register and reference-coordinate findings without changing the scientific argument. Uncured photoresin is a reactive multicomponent mixture whose environmental hazard cannot be inferred from the cured article or from one ingredient safety classification. Ballentine and co-workers measured acute and chronic toxicity of six uncured vat-photopolymerisation resin feedstocks to Ceriodaphnia dubia and found resin-dependent responses across the tested aqueous exposures [1]. Separate SLA studies show that additives can migrate from printed polymer into water and produce developmental effects in zebrafish [2], while printed-part toxicity can be reduced by post-processing without becoming equivalent to uncured-feedstock toxicity [3]. ER-278 defines an ecotoxicity evidence architecture for uncured photoresin constituents and mixtures. It separates intrinsic hazard from realistic environmental exposure, requires mixture and carrier controls, treats solubility and dispersion as measured test conditions, and prevents one aquatic species or one nominal concentration from being converted into a universal environmental-risk conclusion. Terrestrial evidence is explicitly identified as a gap where direct photopolymer data are absent.

ER-278 · Version v0.2.