Where safety data sheets fall down is where the 'user' undertakes a process that was never envisaged by the COSH assessor. An example was Magnavox recording tape.
In normal handling the tape was assessed to have no hazard. I cannot recall if there was a hazard from the tape being subjected to fire, however that was not what we did. Magnavox said the tape posed no problems.
We hacked the spooled tape with a hacksaw so that it was in strips no longer than 18 inches and less. We then put it through volumetric disintegrator. We finished up with a fine powder substance.
We described the process to Magnavox and the answer was a lemon.
The end result, when you considered all the modifications we did to different materials was withdrawal of the disintegrator. It was a Russian device so I guess they hadn't been worried about COSH.