Seven out of 10 businesses in Northern Ireland run the risk of falling foul of an imminent change to the law on fuel storage, research has suggested.
Owners who do not comply with the new regulations, which come into force at the start of next year, could face a fine of up to £20,000 or even imprisonment, the manufacturer which conducted the survey warned.
From January 2016, large volumes of fuel at business premises need to be stored in "double-skinned" tanks - a requirement being introduced to reduce the risk of pollution incidents.
Kingspan Titan, which works in the fuel storage industry, said its research indicated 70% of businesses would not be compliant under the new law.
The company, which sponsors Ulster Rugby, issued the warning at an event at the team's Kingspan stadium in Belfast.
Pat Freeman, managing director of Kingspan Environmental, said: "The cost of oil spillages to both business and the environment can be heavy and the government has taken action to bring Northern Ireland into line with the rest of the United Kingdom.
"It is imperative business owners are made aware of this regulatory change and the consequences of non-compliance.
"Business owners are also often unaware that they will be responsible for the cost of any clean-up required due to an oil spill on their premises, costing many thousands."