The “facts” that Gaspasser posted look like they were from a government (e.g. COT) report or similar. To try and bring some balance, here are some other facts:
1. As early as 1977, a C130 navigator became incapacitated, and further investigation into breathing heated oil fumes was called for.
2. and 3. Agreed
4. and 5. As well as TOCP, oil also contains MOCP and DOCP (mono and di-) which are more toxic and are present in much greater quantities, so any estimation of the toxicity of the oil would have been hugely underestimated.
6. Due to the “wet” nature of their design, no seal can be 100% effective, so there is always going to be some, even if a little, background level of toxins. Some seal designs are better than others and some operators’ maintenance procedures are better than others, so yes, some types or airlines feature more.
Unfortunately the COT studies deal in misinformation and doubt, so any real headway in seeking answers is never forthcoming.