The Road Safety Authority is to replace thousands of high-visibility vests after the garments were found to be "marginally below" the required safety level.
The RSA distributed more than 200,000 vests - bearing the logo Be Safe Be Seen - as part of a safety campaign last year.
However, RSA chief executive Noel Brett confirmed today that a reflective strip on the vests failed to meet the required visibility criteria.
The affected vests can be identified by a tag on the collar containing the name of the manufacturer, Optipro, he said.
Road users with the vests will be able to have them replaced free of charge by the RSA.
Mr Brett confirmed the defective vests were sourced from one supplier following a tendering process.
Around 150,000 of the vests that remained in stock have already been destroyed.
The RSA will began a public notification strategy to make the public aware of this issue and how the vests can be replaced later this month.
Public notices will appear on RSA website and in national newspapers and other publications.
The RSA’s announcement comes after of six people, including four motorcyclists, were killed on Irish roads over the weekend.
