While the occasional snapshot that includes the sun is generally safe, there are certainly combinations of lens and duration that can damage an image sensor if the sun or other sufficiently bright light source is present.

Are there industry standards or specifications for some minimum safe conditions of light exposure at the image sensor's surface? I'm asking about a spec that relates to the intensity at the surface of the sensor, so I'd expect that "industry" refers to sensor manufacturers.

*Loosely speaking:* is there some minimal, established test condition that most sensors can reliably survive without damage?