Especially among growers in the US, the UK, and Australia, there has been a competition since the 1990s to grow the hottest chili pepper. Chili pepper species and cultivars registering over 1,000,000 Scoville Heat units (SHU) are called "super-hots". Past Guinness World Record holders (in increasing order of hotness) include the ghost pepper, Infinity chili, Trinidad Moruga scorpion, Naga Viper pepper, and Trinidad Scorpion Butch T. The current record holder, declared in 2017, is the Carolina Reaper, at more than 1.6 million SHU.