Cyanide was found in two grapes during the 1989 Chilean grape scare.
U.S. inspectors discovered traces of cyanide in two grapes from a shipment of Chilean fruit. The discovery led the United States to suspend imports of Chilean fruit, and consumers were warned not to eat Chilean grapes or certain other Chilean produce while authorities investigated.
The incident caused major disruption to Chile's fruit-export industry, but the contamination was limited to the detected shipment. Investigators did not find evidence of widespread poisoning among consumers. The scare ended after inspections and negotiations led to the resumption of imports.
This event is sometimes remembered as a large poisoning outbreak, but it was primarily a precautionary import ban triggered by a small number of contaminated grapes. Cyanide is a rapidly acting poison, which explains the seriousness of even a limited detection.