Starting the second week of its inquiry into the Blood Transfusion Service Board's decision-making procedures in the 1980s, the tribunal turned its attention to the plight of 200 haemophiliacs infected with hepatitis C.
The board faced a major challenge at the time in combatting the then undefined hepatitis virus, known only as Non-A, Non-B hepatitis until it was formally identified in 1989.
And as with the HIV crisis, the board's actions on hepatitis C were highly questionable.
Common features emerged from evidence yesterday, among them an apparent lack of urgency in addressing the health risk, a paucity of discussion at board meetings on the safety of treatment options, and a concentration on cost rather than the efficacy of safety measures.
It was clear from evidence that if the board had realised by the mid-1980s that it could have done more to prevent HIV infections, which were by then minimal if not non-existent, that realisation was not reflected in subsequent actions - because the same errors on HIV appear to have been repeated.
By 1985 certain methods of creating the blood products factor 8 and factor 9 had emerged as more favourable to others. Doubts were being raised about conventional heat-treatment, which was found to destroy the HIV virus but not hepatitis C, and which the BTSB continued to use until at least 1988.
Among the new technologies were a "solvent detergent" method, developed at the New York Blood Centre in 1985 and adopted by Swiss blood transfusion board the following year; a super heat-treatment procedure pioneered at the British blood transfusion board's Elstree plant also in 1985, and pasteurisation, developed in Germany in 1980 but not used by blood product manufacturers until 1986.
The BTSB's role in exploring these options was examined yesterday in the context of the guiding objective at the time of obtaining self-sufficiency in blood products for haemophiliacs.
The BTSB had initially set a target with the Department of Health of January 1st, 1986, to become self-sufficient, but the Belgian products manufacturers Travenol, who were making factor 8 from Irish plasma, were yielding less product than expected.
An agreement was reached with Armour in 1987 for it to produce factor 8 with Irish plasma under heat-treatment conditions of 68 degrees. The agreement - for which no contract was signed - ran into problems in December 1987 when the company voluntarily withdrew a heat-treated factor 8 product it was making for the Canadian blood board amid infection fears.
Dr Emer Lawlor, the BTSB's deputy medical director, rejected the claim that there were safety concerns over the heat-treated product. Instead, she suggested Armour's decision to move to a new technology was "a commercial decision as much as anything else".
The BTSB continued to receive heat-treated factor 8 from Armour through 1988.
The tribunal will now seek to establish whether any haemophiliacs were infected through this subsequently-imported product, or through by-products which went towards producing factor 9 in Dublin. If any such cases can be confirmed, the implications for the BTSB are extremely serious.