BioRefusalAudit: Auditing Biosecurity Refusal Depth Using General and Domain-Fine-Tuned Sparse Autoencoders
Researchers introduce BioRefusalAudit, a framework using sparse autoencoders to evaluate the structural integrity of language model biosecurity refusals. The study reveals that five tested models fail to cleanly distinguish hazardous from benign biology, with refusals often disappearing under prompt formatting changes or output constraints, and some models refusing based on legality rather than actual biological hazard.