Eat soaked wood ear and snow fungus at the same meal, without keeping them overnight; eat fresh rice noodles such as ho fun and rice noodle rolls on the day of purchase, and do not ferment cornmeal at home

No monetary cost. Soak only as much fungus as you will eat, and discard the leftovers. Buy only enough fresh rice noodles to finish that day. The hard part is discarding excess soaked fungus; some families also have a tradition of making suantangzi, a fermented cornmeal dish.

China's national foodborne disease outbreak surveillance recorded 19 bongkrekic acid poisoning outbreaks from 2010–2020, with 146 illnesses and 43 deaths: a case fatality rate of 29.5%, meaning 29.5% of those who became ill died. By food type, home-fermented cornmeal products accounted for 9 outbreaks and 33 deaths; fresh rice noodles for 5 outbreaks and 7 deaths; and wood ear fungus for 3 outbreaks, 5 illnesses, and 3 deaths. Of the 143 food poisoning deaths reported nationally in 2020, 12 involved bongkrekic acid, behind poisonous mushrooms at 80 and methanol at 14. Beijing's market regulation authority states that neither boiling at 100°C nor pressure cooking destroys bongkrekic acid, and there is currently no specific antidote. Since 2018, Guangdong has required sealed small packages and clearly marked shelf lives for fresh rice noodles. A before-and-after comparison found that average annual cases across the province fell from 6.25 to 0.5.

Zhang H 等 (2023). Epidemiology of foodborne bongkrekic acid poisoning outbreaks in China, 2010 to 2020. PLoS One 18(1):e0279957：「From 2010–2020, a total of 19 BA poisoning outbreaks were reported to the China National Foodborne Disease Outbreak Surveillance System. These outbreaks involved 146 illnesses, 139 hospitalizations, and 43 deaths, with a case-fatality rate of 29.5%.」https://doi.org/10.1371/journal.pone.0279957 ; Li H 等 (2021). Characteristics of Settings and Etiologic Agents of Foodborne Disease Outbreaks — China, 2020. China CDC Weekly 3(42):889-893. https://doi.org/10.46234/ccdcw2021.219 ; Yuan Y 等 (2020). A Foodborne Bongkrekic Acid Poisoning Incident — Heilongjiang Province, 2020. China CDC Weekly 2(51):975-978：「In October 2020, 9 persons in Jidong County, Heilongjiang Province died after consuming a homemade fermented corn flour product — sour soup — with a case fatality rate of 100%.」https://doi.org/10.46234/ccdcw2020.264 ; Liu Z 等 (2026). Controlling the Storage Time Is an Effective Measure to Reduce the Risk of Bongkrekic Acid Poisoning Caused by Wet Rice Noodles. Foodborne Pathog Dis 23(7):468-472（2025-05-12 网络首发）：「The annual average number of BKA poisoning cases in Guangdong Province dropped from 6.25 before implementing the code to 0.5 after implementing the code.」https://doi.org/10.1089/fpd.2024.0131 ; 北京市市场监督管理局 (2023). 关于米酵菌酸引发食物中毒的风险提示：「米酵菌酸对热稳定，经100℃煮沸和高压烹饪也不能被破坏」「目前，尚无米酵菌酸特效解毒药物」「隔天泡制的银耳、木耳及其加工制品不能食用」「耳片不成形、发粘、无弹性或有异臭味的不能食用」「尽快催吐，排出胃内容物，减少毒素的吸收量；及时送医院救治」. https://scjgj.beijing.gov.cn/hdjl/xfts/202309/t20230904_3248296.html ; 湖南省市场监督管理局 (2025). 【食安科普】米酵菌酸致命警告：「银耳冷水（室温）浸泡3~4小时，木耳冷水浸泡1~2小时，中途换水1~2次，去除微生物，泡发时长最长均不能超过8小时」「若浸泡后银耳、木耳摸起来黏黏的，弹性差，有酸臭异味，泡发水浑浊，是变质的表现，应立即丢弃」「当中毒发生时，应第一时间催吐，减少毒素的吸收；尽量保存可疑的致病食物，并及时就医」「吃了同样食物的人，不管有没有症状，都应送医院检查」. https://amr.hunan.gov.cn/amr/xxx/xtdtx/202506/t20250630_33725786.html ; 贵州省市场监督管理局 (2023). 关于谨防米酵菌酸中毒的食品安全警示：「选购银耳、木耳等相关食品时，要选择正规渠道，泡发不可过夜，应及时加工食用」. https://amr.guizhou.gov.cn/zfxxgk/fdzdgknr/tzgg_5626971/tzgg_5626972/202307/t20230728_81318622.html

In October 2020, several families in Jidong County, Jixi, Heilongjiang, ate homemade suantangzi for breakfast. All 9 people who ate it died. One or two hours in cold water is enough to soak wood ear fungus. Local advice on maximum soaking time varies; Hunan specifies no more than 8 hours. If the fungus is slimy, has lost its elasticity, smells sour or foul, or the soaking water is cloudy, discard the whole batch. If vomiting, dizziness, or generalized weakness develops after eating, induce vomiting immediately and take the leftover food to hospital. People who ate together should also be checked even without symptoms. For wild mushrooms, see Item 5 (do not eat wild mushrooms). Site note: The cited Chinese risk notices recommend inducing vomiting, whereas general poisoning guidance from the NHS and the NSW Poisons Information Centre advises against doing so because of choking and aspiration risks. For suspected poisoning, seek emergency or poison-specialist advice immediately. Do not induce vomiting based solely on this entry or delay medical care. Source