MTA officials say the fumes that suspended L train service were not toxic.

"It is not toxic in any way, it may be obnoxious to the people to smell the fumes... but it is not in any way toxic or unsafe," says MTA Safety Chief Pat Warren.

The MTA suspended service Tuesday afternoon in both directions between Myrtle Avenue and Eighth Avenue in Manhattan for the FDNY and Department of Environmental Protection to investigate the smell. L train service was restored by Tuesday evening.

MORE:  L train service returns to normal following fuel smell investigation

Officials say the air quality in the station was safe. Passengers and two MTA workers reported feeling sick, nauseous and possibly lightheaded when they smelled the fumes in the station.

Warren says despite the smell making people feel ill, it does not pose a health threat. He says the source of the smell was found to be some kind of oil coming up from the ground but was unclear on where it was coming from.

The MTA says it's putting down blankets and pads onto parts of the track to try and absorb some of the oil, and installed fans at the station on Graham Avenue to try and circulate the air.