The Health and Safety Executive which set up a helpline for people concerned over the Castlerock gas leak has so far received almost two hundred calls.
The HSENI said it had had a "strong response" to its emergency helpline number.
It said that more than "185 calls have been received so far from concerned members of the public".
The emergency helpline is 0800 0320 121 and will operate until midnight on Tuesday.
A warning has been issued to anyone who has had gas work carried out by a Coleraine company.
It follows a Health and Safety Executive investigation into the deaths of two Newtownabbey teenagers at an apartment in Castlerock last week.
The HSE is advising anyone who had work done by George Brown, trading as George Brown of 'The Calor Shop' in Coleraine, to switch off all gas appliances.
'The Calor Shop' is an entirely separate legal entity to Calor Gas (NI) Limited.
On Monday, the HSENI said a liquid petroleum gas appliance in the flat where the teenagers died was defective.
Aaron Davidson and Neil McFerran, both 18, died in a Tunnel Brae Court apartment last Tuesday following a suspected carbon monoxide leak.
Their friend, Matthew Gaw, survived.
Aaron Davisdon's aunt, Yvonne Best, owns the apartment in Castlerock.
Ms Best said she had felt ill after visiting the holiday home.
"I felt dizzy and nauseous and blacked out, but put it down to a previous illness," she said.
"After returning to the apartment again I blacked out and I went to the doctors and had some tests, I never thought it was anything to do with the apartment, just my own personal health.
"I feel so guilty. I've spoken to their parents and they said they don't blame me", Ms Best added.
"My head tells me I didn't do anything wrong but my heart tells me it was my apartment that killed them.
"So I feel guilty and it will be with me for the rest of my life, and I'm so sorry these boys had to give their lives.
"The worrying thing is there are no symptoms for carbon monoxide poisoning and I would urge everyone to remember that."
HSENI said it was continuing to carry out checks in other premises in Castlerock and Coleraine.
The HSENI has asked that only members of the public with specific emergency safety concerns use the helpline.
In a statement on Monday, the safety body also issued some general advice and said anyone displaying any of the following symptoms - headache, dizziness, nausea, breathlessness, collapse, loss of consciousness, should seek medical help immediately.
They should also contact their local Gas Safe registered engineer and request a full gas safety check.
The HSENI also advised installing an audible carbon monoxide (CO) alarm as a further precautionary measure.
The funeral service for Aaron Davidson took place at The Church of the Ascension, Newtownabbey on Monday.
A funeral service for Neil McFerran was held at Newtownabbey Methodist Mission in Rathcoole on Saturday.
Meanwhile, Enterprise Minister Arlene Foster has said she hoped to meet the finance minister this week to discuss building control regulations which would make carbon monoxide detectors mandatory in all new-builds.
She said "that, of course, would be the case for smoke alarm detectors for new-build properties and I think it should be reflected for carbon monoxide detectors as well".