Cervical cancer campaigner Lorraine Walsh has said that it is crucial that the recommendations on quality assurance made by Dr Gabriel Scally in his second report must be implemented.
Only then could women have confidence in the system in Ireland, she told RTE radio’s Morning Ireland.
The second report of the Scally inquiry, published on Tuesday, found wider outsourcing of screening tests, with 16 laboratories being used rather that the six that were originally identified.
Some of the laboratories to which tests were outsourced no longer exist.
Ms Walsh said she was disturbed by the findings of the second report and said if Dr Scally's review had gone on longer, he could have found more labs involved.
Given that Dr Scally could not visit some of the labs, he would not know whether they were suitable or not, and so the full answers would never be known, she added.
People like she and Vicky Phelan, whose smear tests went to Texas, will never know where they were actually read, she said.
Ms Walsh said that if Dr Scally's recommendations are implemented correctly, and a robust system is put in place, then women can have confidence.
She said the 221+ group has asked the Health Service Executive to state that from a clinical perspective it has confidence that slides going abroad are safe. “The HSE has to nail its colours to the mast and declare that it is safe.”
Meanwhile, a spokesperson for The Academy of Clinical Science and Laboratory Medicine has expressed surprise and disappointment at the findings in the (second) Scally report.
Laboratory Manager at the National Maternity Hospital Marie Culliton said it is extraordinary to discover, that 16 months after the first problems arose, that there were 16 labs checking Irish smear tests and this outsourcing was unknown to the national cervical screening programme.
She told Morning Ireland that she welcomed the fact that there are no concerns over the quality of the testing, but that it was alarming that laboratories were not forthcoming about the outsourcing and that there was retrospective accreditation of one lab.
Ms Culliton explained that accreditation sets specific criteria as to how the laboratory should be structured and run but does not assess the quality of the work or the proficiency of the staff.
This problem dates back to 2009 and it is not known whether there is "a cluster of error associated with any year, with any particular provider or, within those providers, with any of their individual laboratories or the staff within those".
Ms Culliton warned that Dr Scally's review could be the "tip of the iceberg" because it is not known how many women who have had smears reported as negative subsequently went on to have a positive smear and it was impossible to re-examine all of the tests that have been carried out.
Errors happen for a number of reasons and these errors need to be investigated to ensure that they do not happen again, she said, but this must happen in a safe space so that people do not feel "forever under pressure".
The people who carry out the tests are qualified professionals and they want to do it right, she said.