New York is pursuing producers of oils used in vaping products. (Frank Franklin II/AP)

New York Gov. Andrew M. Cuomo (D) said Monday he is ordering the state health department to issue subpoenas to three companies the department has identified as selling substances linked to the mysterious vaping-related lung illnesses that have sickened hundreds of people across the country.

The companies are marketing and selling “thickening agents” that can be used in black market vaping products that contain THC, the active ingredient in marijuana that produces the high. Dealers have been using thickening agents to dilute THC oil in street and illicit products, industry experts said. These thickeners are being marketed and readily available on the Internet “as a cheaper, safer alternative that does not negatively impact flavoring or odor of existing products and can be used to cut vape products to any level of THC,” the governor’s office said in a news release.

New York state’s lab obtained samples of thickeners from three companies and determined they are “nearly pure” vitamin E acetate, an oil derived from vitamin E. Federal and state authorities have identified vitamin E acetate as a potential clue in the unfolding mystery because it is a common element in cannabis products that have been collected from patients who have fallen ill.

Investigators at the U.S. Food and Drug Administration have found the oil in cannabis products in samples collected across the United States. That same chemical was also found in nearly all cannabis samples from patients who fell ill in New York in recent weeks, state health officials said. Although the FDA does not have enough data to conclude that vitamin E acetate is the cause of the lung injury, the agency said late Friday that “it is prudent to avoid inhaling this substance.”

It is the first common element found in samples from across the country. While health officials have said it is too early to know whether the oil is causing the injuries, New York state has said vitamin E acetate is a key focus of its investigation.

Vitamin E is found naturally in certain foods, such as canola oil, olive oil and almonds. The oil derived from the vitamin is commonly available as a nutritional supplement and is used in topical skin treatments. It is not known to cause harm when ingested as a vitamin supplement or applied to the skin. Its name sounds harmless, experts said, but its molecular structure could make it hazardous when inhaled, and officials said it could be associated with the kinds of respiratory symptoms that many patients have reported: cough, shortness of breath and chest pain.

The companies being served with the subpoena are Honey Cut Labs in Santa Monica, Calif., for its Honey Cut Diluting Agent; Floraplex Terpenes in Ypsilanti, Mich., for its Uber Thick agent; and Mass Terpenes in Amherst, Mass., for its Pure Diluent.

The governor’s office said these three companies are the first to be subpoenaed, but more companies are likely to be ordered to provide samples as the investigation continues. Health authorities want the companies to provide additional information to aid the ongoing investigation.

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