Chairman of Ash Ireland Dr Ross Morgan has said the introduction of plain packaging for cigarettes would contribute towards a drop in people taking up smoking.
Dr Morgan, a consultant respiratory physician, said the proposed legislation was ground-breaking.
He told the Joint Oireachtas Committee on Health and Children that the tobacco industry tries to convince people that it does not target young people in its marketing, but this was not the case.
He said plain packaging would no doubt make it harder for the industry to market their products.
Kathleen O'Meara from the Irish Cancer Society said plain packaging would reduce the appeal of cigarettes to young people and would stop smokers thinking some brands were less harmful than others.
She said it would discourage people from smoking and it would increase negative feelings around tobacco.
Ms O’Meara said the Irish Cancer Society had conducted research with the Irish Heart Foundation on groups of young people aged 15 and 16 and this showed that they were influenced by branded packs.
Chris Macey from the Irish Heart Foundation said the legislation would save the lives of untold numbers.
He accused the tobacco industry of funding groups such as retailers and grassroots organisations to lobby for them.
Sharon Cosgrave, CEO of the Asthma Society of Ireland, said tobacco was a unique product in that it caused the death of half of its users.
She said asthma cost the state €262m each year in lost work days.
Damien Peelo from COPD Ireland, which represents people with chronic obstructive pulmonary disease, said it was imperative to stop people taking up smoking and the swift introduction of the legislation would prioritise that.
Independent Senator John Crown said people who were selling cigarettes were part of the problem and he suggested the Government incentivise the retail trade to make shops tobacco-free by giving them a different VAT rate.
Ms O'Meara said there was an incredible amount of lobbying by the industry over the EU Tobacco Products Directive.