The LE Niamh naval vessel has retrieved a number of bags of bird seed from the water in its search for a number of containers that went overboard from a cargo vessel yesterday.
So far there have been no sightings of the seven 40ft containers, which fell into the sea off the south coast about 20 miles off Tramore.
The containers were carrying bird food, fire logs, medical equipment and one contained the hazardous material Sodium Bromate.
The Coast Guard helicopter is searching again this afternoon and the LE Niamh remains in the vicinity.
Naval officers on board the LE Niamh say the missing containers are undectable by radar. It is believed that they have all sunk.
Some floating objects were found in the area that are consistant with the contents of the missing containers.
Shoreline searches by the coastguard units in Tramore, Bunmahon, Helvick, Ardmore and Youghal are currently being hampered by a bad fog in the area and will resume in the morning.
Members of the public are being urged to stay at least 100m away from the containers, should they happen to come ashore over the next few days.