And I had the same problem with 635nm red LEDs. The CD/DVD test showed small pure blue and pure green spikes that led to unexplained fogging. The unaided eye could not see these. I then tried a single thickness of standard Rubylith as the filter. That did the trick. My tested safe time under the red LEDs (for both Ilford MGIV FB & RC) went to over 60 minutes.

Ken