MIT chemistry building shuttered for 4th day after grad student claims to have synthesized deadly neurotoxin

A Massachusetts Institute of Technology graduate student's claim to have synthesized dimethylmercury — considered the most potent neurotoxin in the world — has kept a campus chemistry building closed for more than four days.

According to the Boston Globe, the student walked into an emergency room on Wednesday night and told staff he had synthesized the compound. MIT said the student had no authorization to handle the substance and that it was not part of any assigned research.

Cambridge fire department radio logs captured a firefighter reporting: "There is an unknown clear liquid on the laboratory floor. The lab has been isolated and all personnel in the area have been evacuated."

However, MIT said in a public notice that it questioned whether the compound had actually been synthesized, adding that initial blood tests showed no signs of mercury exposure.

Dimethylmercury is an organomercury compound consisting of a single mercury atom bonded to two methyl groups. It is a colorless liquid at room temperature with a faint sweet odor.

According to the US Occupational Safety and Health Administration, absorbing less than 0.1 milliliters can cause fatal brain damage or death — roughly the equivalent of two drops of water, given that a single drop is about 0.05 milliliters. The compound can enter the body through the skin or by inhaling its vapor.

Because it is fat-soluble, it penetrates latex, PVC and neoprene gloves on contact. It accumulates in fatty tissue before slowly migrating to the brain, meaning an exposed person may feel no symptoms for months.

The substance has claimed lives before. In 1996, Karen Wetterhahn, a chemistry professor at Dartmouth College, spilled one or two drops of dimethylmercury onto her latex glove while transferring the compound. She fell into a coma within weeks and died in 1997.

Two laboratory assistants working in Edward Frankland's lab in Britain died in 1863 while preparing the substance, and a Czech chemist died in 1972.

Meanwhile, MIT said it considers the risk of further exposure to be low. The university is continuing decontamination work at the chemistry building where the incident occurred.