The risks of eating puffer fish, also known as blowfish, mainly come from tetrodotoxin (TTX), a biotoxin that puffer fish may contain.
TTX is a heat-stable toxin, and its structure cannot be destroyed by cooking.
TTX can affect a person’s central nervous system, and in severe cases, death can occur. So far there is no antidote for TTX poisoning.
According to the import system of Macao, imported fish products are subject to mandatory inspection and quarantine before they are allowed to enter local markets.
The sector is obliged to ensure that the food it supplies is safe and does not contain any substance that may pose a hazard to human health.
The public should purchase fish and their products from reputable sellers, and avoid purchasing and handling wild puffer fish by themselves or consuming unknown fish, so as to prevent food poisoning caused by TTX.
In the past, there were occasional reports of puffer fish poisoning in neighbouring regions. Accordingly, different regions have rolled out policies in recent years to regulate the processing and operation of puffer fish to ensure food safety for consumers. In fact, there have been inquiries from the sector in Macao over the years regarding the safety of puffer fish consumption, indicating that the topic has drawn much attention.
Puffer Fish and Its Consumption Risks
The risks of eating puffer fish, also known as blowfish, mainly come from TTX, a biotoxin that puffer fish may contain. Many species of puffer fish contain TTX in their bodies. The toxicity and distribution of TTX in tissues vary with species. In general, TTX is more concentrated in the viscera, ovary, blood, head and skin of puffer fish, while the muscles and spermary are non-toxic or low-toxic. Puffer fish are more toxic in spring, the spawning season, and this is also the season when TTX poisoning is most likely to occur. Some other species of aquatic organisms, such as gobies and shellfish, may also contain TTX.
TTX is a potent nonprotein neurotoxin. Studies have shown that it is over 1,000 times more toxic than cyanide. A single dose of 0.5 mg of TTX can be lethal. In addition, TTX is a heat-stable toxin, and its structure cannot be destroyed by cooking.
The clinical symptoms of poisoning generally occur between 10 minutes and 3 hours from accidental ingestion of puffer fish containing TTX. The symptoms include numbness of the lips and mouth, or tingling in the fingers and limbs, followed by nausea, emesis, slurred speech, motor imbalance, muscle weakness and paralysis. In severe intoxication, death can result from respiratory failure. The victim, although entirely paralysed, may be conscious and completely lucid until death. So far there is no antidote or antitoxin for TTX poisoning, and symptomatic treatment and supportive therapy are the main treatment means.
State of Regulation
According to Law No. 5/2013 “Food Safety Law”, the sector in Macao is obliged to ensure that the food supplied is safe for consumption. To this end, the sector has the responsibility for formulating appropriate risk prevention measures according to the food types, so that the food sold does not contain any substances, such as biotoxins, that may pose a hazard to human health. In accordance with the import system of Macao, all imported fish must be declared in advance to the competent authority and are subject to mandatory health inspection and quarantine. The importer must make an appointment for the inspection and present a valid health certificate issued by the competent authority of the place of origin, to show that the product meets the health requirements and is fit for consumption.
In mainland China, except for artificially bred puffer fish bases and processing enterprises that have been approved by national authorities to produce or process Takifugu rubripes and Takifugu obscurus, it is prohibited for any unit or individual to produce (process) or operate puffer fish. The puffer fish are not sold alive in mainland China; instead, only fish products that have been detoxified can be found in the mainland China market.
Countries such as the United States, New Zealand, and Singapore have strict restrictions on the import of puffer fish for dietary use. In addition, there is currently no internationally recognised standard for the preparation guidelines, processing procedures and certification methods of puffer fish products to ensure that they remain completely TTX-free during the preparation process.
Advice for the Sector and the Public
The sector is obliged to ensure that the fish and products thereof supplied are safe for consumption;
The public should purchase fish and products thereof from reputable sellers;
The public should avoid purchasing and handling wild puffer fish by themselves or consuming unknown fish, so as to prevent food poisoning caused by TTX;
Go to the hospital to seek treatment as soon as possible if any symptom arises after eating puffer fish.
1. Puffer Fish and Food Containing Puffer Fish (Centre for Food Safety of the HKSAR Government). 20 August 2021
2. Tetrodotoxin – the Deadly Poison in Puffer Fish (Centre for Food Safety of the HKSAR Government). 18 May 2021
3. Tetrodotoxin and Regulation of Puffer Fish as Food in Other Places (Centre for Food Safety of the HKSAR Government). 28 February 2014
4. Beware the Fatal Tetrodotoxin of Mudskipper-like Toxic Gobies (Centre for Food Safety of the HKSAR Government). July 2018
5. “Notice on Conditionally Lifting Restrictions on Processing and Operation of Takifugu rubripes and Takifugu obscurus” (Ministry of Agriculture and Rural Affairs of the People’s Republic of China). 7 September 2016
6. “Research Progress of Edible Safety and Nutritional Value of Puffer Fish”. Acta Agriculturae Shanghai, 2012, 28(2): 123–128
7. Prevention of Puffer Fish Poisoning (Dongguan Municipal Center for Disease Control and Prevention). 23 March 2015
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