Chlorinide was a liquid chemical substance used by the Federation. While harmless to humanoid life if leaked in small quantities, chlorinide was highly corrosive and could cause malfunctions to cargo safety systems. Leaks were difficult to pinpoint by a standard tricorder scan.
The USS Enterprise-D carried several barrels of chlorinide in 2368. The chlorinide began to leak from a series of containers stacked on a shelving unit, causing the support structure to break and the barrels to fall. Lieutenant Commander La Forge and Lieutenant Worf searched for the leakage, and unfortunately Worf was standing beneath the affected barrels when they fell. Several of his vertebrae were crushed and his spinal cord severed, temporarily causing him to become a paraplegic. (TNG: "Ethics")