Jake Molloy, Regional Organiser of the OILC union, told STV on Monday that if reports of gas bubbling up through the water under the platform are true then the situation is likely to be "very volatile".
He said there may be a risk of explosions and of the poisonous gas hydrogen sulphide, although added that the evacuation had been quick and efficient.
More top news
First Minister Carwyn Jones revealed in his plans in his speech to the Welsh Labour conference.
Army personnel have praised Prince Harry for changing lives ahead of this year's Invictus Games in Sydney.
Dry and sunny for most, however, some isolated heavy and thundery showers will develop.