Sodium hydroxide is also known as lye and can be deadly if ingested in large amounts. Advertisement\"The hacker changed the sodium hydroxide from about one hundred parts per million, to 11,100 parts per million,\" Gualtieri said, adding that these were \"dangerous\" levels. In smaller quantities, sodium hydroxide can cause severe skin burns and eye damage. That instance of remote access was brief, but then it happened again at 1:30 p.m., and the hacker changed the sodium hydroxide levels, Gualtieri said. AdvertisementJessica Mackesy from the Pinellas County Sheriff’s Office told Motherboard in an email that the remote access software used was TeamViewer.