Make sure the fogging test was good:

I used red LEDs from superbright to make my DIY safelight, but keep in mind while 635nm might be the peak output these are not typically "sharp cutting" so there is typically an emission band around the stated wavelength. Paper sensitivities might not cut off sharply either, and may extend to higher wavelengths than expected. So a good test of safe time is necessary with any light source.