At least one in four drinks containers sold to customers are not being recycled through the Deposit Return Scheme, latest figures from Re-turn indicate.
It means millions of euro a month are still not being claimed under the scheme.
The latest figures show that 111 million drinks containers were returned in August, putting €20m back in consumers' pockets that month.
It brings the total number of returned containers to 458 million, with €79.7m of customers' deposits returned to them.
The Deposit Return Scheme’s transition period ended on 31 May.
Since then, all drinks containers sold in Ireland are required to have the Re-turn logo.
While the number of drinks containers returned every month has been increasing, the rate at which it is increasing has been slowing down.
A total of 78 million containers were returned in May, the last month of the transitional phase.
This increased by 12 million in June, to 90 million.
Some 102 million containers were returned in July, a similar increase of 12 million.
Last month’s 111 million returns saw an increase of nine million containers on July’s figures.
The Government has previously said that around five million drinks containers are sold every day, or around 150 million a month.
However, this fluctuates throughout the year, with the summer months typically busier.
Re-turn said that peak periods, such as Christmas and summer, "significantly impact sales".
In a statement, it said that "the assumption of an equal number of containers sold daily" throughout the year "doesn't align with the actual sales pattern of drink containers".
The figures also indicate that at least one in three containers have not been returned in the combined months of June, July and August, when it was mandatory to sell containers with the Re-turn logo.
A total of 303 million containers have been returned during that time.
Denmark’s bottle return system, which enjoys a 92% return rate, calls the months of June, July and August "peak season" as it says that is when most bottles are returned.
Despite the number of unclaimed deposits, industry sources have said the progression has shown that the scheme is working well.
CEO of the Convenience Stores and Newsagents Association Vincent Jennings said the uptake of the Deposit Return Scheme is going to be "a slow burner".
Regarding why the current return rate lags behind that of countries such as Denmark, Mr Jennings said "you have to compare like with like".
"For countries like Denmark and Norway, to get to those levels was not 0 to 90. It took a lengthy period of time to get there and I imagine the current rates in Ireland are within [Re-turn's] own projections.
"It is probably going to take two to three years to get to those levels.
"That said, there is still a considerable amount of people who are willing to throw away the money."
Mr Jennings called on the Government, as part of the Budget, to extend the Accelerated Capital Allowance to the Deposit Return Scheme.
This would allow more retailers to purchase machines and extend the scheme to more locations.
Drinks containers returned through the Deposit Return Scheme each month:
- 2m containers in February
- 20m containers in March
- 51m containers in April
- 78m containers in May
- 90m containers in June
- 102m containers in July
- 111m containers in August
Read more:
RTÉ Brainstorm: 5 things our Deposit Return Scheme can learn from other countries
347 million containers returned since Deposit Return Scheme launched
Deposit Return scheme showing strong growth four months on
