I really cannot understand how IATA and IFALPA can accept this on PAX flights, and worse, ETOPS flights. Leaving the PIC with a difficult and uncomfortable decision to make.
IFALPA is co-author of the ERG "RED BOOK" and accepts this practice.
In the end, I am the last in the chain of safety considerations and events, the one to finally accept or decide if is safe of not to fly. The PIC, and not ICAO, IATA, IFALPA or Company (operator) is the PERSON responsible for the safety of the flight, aircraft and all persons and cargo onboard. But if IATA and IFALPA does not impose limitations, the operator is happy and the PIC is considered too conservative and not productive, if he/she says NO and makes the company loose $.
http://www.icao.int/safety/Dangerous...P.020.4.en.pdf