Alcohol adulterated with an antifreeze ingredient, methanol, has poisoned at least 41 people in Costa Rica.

According to the nation’s Ministry of Health, 20 people have died from consuming the tainted booze. Most were Costa Rican men, but at least one was from Nicaragua. Five victims were women. The province hit hardest was Carthage, which saw five deaths. Four deaths were reported in Limón and another four in San José.

Methanol appears clear and usually produces no scent. Manufacturers may have illegally added methanol to alcoholic drinks to boost their potency, USA Today reported. 

Methanol is chemically similar to ethanol — the kind of alcohol found in booze — but the slight difference makes methanol incredibly toxic. Consuming methanol can induce blindness, seizures, heart attacks, respiratory failure, or comas.

The Hard Rock Hotel chain responded to the poisonings by removing all liquor dispensers from its lodging. Brands confiscated by the Costa Rica Ministry of Health for suspected methanol tainting include Aguardiente Estrella, Guaro Gran Apache, Molotov Aguardiante, Aguardiente Timbuka, and Guaro Montano. A total of 30,000 bottles have been confiscated so far.

Vendors caught selling these brands “could face criminal sanctions,” CBS News reported.

In the nearby Dominican Republic, the FBI is conducting toxicology tests on two Americans who recently died there from suspected methanol-spiked beverages. Authorities in the Czech Republic, Norway, India, and Turkey have also discovered methanol illicitly added to brand-name booze. 

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