---
title: "Anthropic's chem/bio weapons filter was off for nearly a year"
url: https://www.parallelquant.com/posts/anthropic-s-chem-bio-weapons-filter-was-off-for-nearly-a-year-7e74fc
source_name: "The Decoder"
source_url: https://the-decoder.com/anthropics-bio-weapons-filter-was-down-for-nearly-a-year-exposing-133-million-requests/
published: 2026-08-16T07:20:06.000Z
topics: ["security", "policy"]
publisher: "Parallel Quant"
---

# Anthropic's chem/bio weapons filter was off for nearly a year

*2026-08-16 · Source: [The Decoder](https://the-decoder.com/anthropics-bio-weapons-filter-was-down-for-nearly-a-year-exposing-133-million-requests/)*

Anthropic disclosed that its internal filter for detecting biological and chemical weapons risk was inactive for close to a year, during which roughly 50,000 external contractors ran about 133 million unfiltered interactions with its models. The company revealed the lapse in a safety report.

**Why it matters:** This is a rare disclosed failure of a frontier lab's own safety infrastructure rather than a hypothetical risk - it's a useful data point against the narrative that leading labs run continuously-verified safeguards, and raises questions about how such gaps get caught, or missed, in practice.

**Topics:** security, policy

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Read the original: https://the-decoder.com/anthropics-bio-weapons-filter-was-down-for-nearly-a-year-exposing-133-million-requests/
Canonical: https://www.parallelquant.com/posts/anthropic-s-chem-bio-weapons-filter-was-off-for-nearly-a-year-7e74fc
Published by Parallel Quant — https://www.parallelquant.com