Times and concentrations?
There's no indication in the Flight Global report of the concentrations of TCP in the air of the aircraft, or how long it took for the amount they found to accumulate. Is it a long-term slow release, or occasional rapid release (isolated "smoke or fume" events)? So it doesn't seem possible to work out the exposure to people, let alone the hazard of that exposure, from what has been found so far.
It could be high exposure and significant hazard, or low exposure and no hazard. More Research Needed, panic not justified by this evidence yet.