In recent years, food contamination by using harmful preservatives in all of the perishable food items like fruit, milk and fish has been going on unabated due to some unscrupulous traders’ ill intentions and also indulgence by government negligence to check the trends.  Many sellers spray their fish with formalin, which is usually used for preservation of tissues. It makes the fishes stiff and giving these a fresh look for longer periods of time.

Formaldehyde is a naturally occurring substance in the environment made of carbon, hydrogen and oxygen. Natural processes in the upper atmosphere may contribute up to 90 percent of the total formaldehyde in the environment.

Formaldehyde can be found naturally or sprayed in food including fruits and vegetables, meats, fish and other dried and preserved foods. The body can metabolize formaldehyde quickly and the substance is converted into formic acid. However, if ingested in huge amounts, formaldehyde is highly toxic especially to a person with weak liver or kidney.[1]

The widespread use of formalin, in preservation of fish, fruit and other food items is posing a threat to public health. The chemical used as a solution in water keeps fish fresh and makes fruits like mangoes attractive. This chemical, usually used to stop dead bodies from rotting, is now being used to preserve edible items.

Physicians have stated in different news media that the regular consumption of formalin-laced fish increases chance of malignancy and neurological impairment or brain functions. Dr Umme Ara, principle scientific officer of the institution of Food Science and Technology of the Bangladesh Council of Scientific and Industrial Research (BCSIR), says to Xtra that formalin may cause uncontrolled cell growth or cancer in stomach, lung and respiratory system if anyone consumes fish contaminated with it.

Exposure from its gas or vapor can cause irritation to the eyes, nose and respiratory tract, causing sneezing, sore throat, larynx constriction, bronchitis and pneumonia. Multiple exposures can lead to asthma. It can also affect the skin, causing dermatitis or allergic reaction. Serious inhalation or ingestion can cause severe pain with inflammation ulceration and necrosis of the mucous membranes, which line almost every internal organ. This may show as symptoms of nausea, vomiting blood, diarrhea with bloody stool, blood from the urine, acidosis, vertigo, and circulation failure, then death. 30mL is suggested the lethal dose of formalin. The limit allowed in air that is still safe for human is less than 2 ppm.

Formalin that was recently found in food, might not give such obvious reactions. However, this substance is known to be a carcinogenic substance, can precipitate cancer. A study showed mice exposed to formalin with concentration of 6 to 15 ppm for 2 years developed squamous-cell carcinoma in the nostril. Some other studies also show formalin will cause kidney, liver, and lung problems.[2]

The role of fisheries and livestock sectors in the development of agro-based economy of Bangladesh is very important and promising. They contribute around 8% to national income, which also is 32% of the total agricultural income. About 90% of animal protein in our diet comes from fish and livestock. The fisheries sector contributes 5.10%, of the country's export earnings, 4.91% of its GDP and provides 63% of the national animal protein consumption. Fish and fishery products are the country's third largest export commodity contributing 5.10% of its exchange earnings, in 2002–2003 Bangladesh earned US$ 324 million of which shrimp alone contributed 72% of the total by quantity and 89% by value. It is claimed that the total fish production has increased significantly over the last few decades but it is not sufficient to meet up the growing demand of the country. As a result imported fishes from neighboring countries enter in the domestic market and it was reported that more than 80 metric ton of fish and fishery products enter into Bangladesh every day through the Teknaf border from Myanmar. Available reports suggest that formalin is sometimes added or sprayed to the fishes by the fish traders while transporting to domestic marketing chain to prevent spoilage and increase shelf life. Studies conducted at different markets in Dhaka city and Mymensingh Sadar rationalizes the incidence of adding formaldehyde/formalin to fishes especially imported from neighboring countries.It was observed in a study conducted in Dhaka city that almost 5% shops of total consumable fishes contain formalin treated fishes those are sold in fish markets. They found this intensity to vary market to market and species to species. They found that Rui fish was highly affected by formalin whereas Karwan Bazar represented highest number of formalin treated fish. In this current study mainly big fish species were investigated which indicated a high percentage of presence of formalin in fish.[4]

Unabated sales of adulterated foodstuffs posing high health risks worry consumers across the country. The excessive use of chemicals like formalin, calcium carbide, pesticides and artificial growth regulators on a wide range of products from fruits to fish to vegetables keep consumers wonder where to buy safe food. They have long been complaining about the use of formalin on fish and tomato, and applications of carbide and growth regulators on banana, pineapples and other fruits. "I tend not to buy banana, pineapples these days for my daughter because of harmful chemicals they [producers, marketers] use to forcibly ripen and preserve those,” said SK Chowdhury, a resident in the city's Dhanmondi area.

“We also feel unsafe while buying fish like rui, katla and mrigel as the fishmongers apply formalin to fishes." Agronomist Shahidul Islam, a consultant of UN Food and Agriculture Organization (FAO), said environment pollution as well as the use of chemicals like formalin and carbide on food items poses serious health hazards to consumers. Brac Executive Director Mahbub Hossain, also an analyst of farm economy and food security, told The Daily Star that while Bangladesh showed much prospect in ensuring availability of food and keeping the prices within purchasing ability of people, food adulteration has become a big threat to food security. Under a project titled “Improving Food Safety, Quality and Food Control in Bangladesh”, the FAO two years ago assessed the capacity of the ministries and agencies involved in food inspection and enforcement. The assessment revealed food inspection in Bangladesh is not based on risk assessment and inspection actions don't cover the entire food chain. Participants at a FAO-organised food safety stocktaking meeting noted that food standards are certified by Bangladesh Standards and Testing Institution. The existing standards are to a large extent obsolete, quality oriented and overlapping and don't cover the most common food products, they observed.

Limited coordination and communication between the enforcement agencies has been identified as one of the main food inspection challenges. The lack of coordination between the agencies is considered a cause of both gaps in inspection and overlapping  enforcement activities. [5]

Formalin inside?

  • Other sea products, including dried salty fish. Formalin will make the fish become stiff, whitish and odorless. Even when cooked, i.e. fried, it will still be stiff.
  • Wet noodles. Has yellowish color, tends to be elastic, with a drug-like odor or ash-like odor when boiled or mixed with hot water.
  • Fish, especially sea fish. Press the fish, if it feels tender, it should be free of formalin. Choose fish which still has its fishy smell. It’s best to buy live fish.
  • Avoid dried salty fish.
  • Wet noodles. Try the less attractive colored ones.[2]

How to avoid food with formalin?

  • Fish, especially sea fish. Press the fish, if it feels tender, it should be free of formalin. Choose fish which still has its fishy smell. It’s best to buy live fish.
  • Avoid dried salty fish.
  • Wet noodles. Try the less attractive colored ones.[2]





3) Uddin R, Wahid MI, Jesmeen T, Huda NH, Sutradhar KB. 2011;Detection of Formalin in Fish Samples Collected from Dhaka City, Bangladesh;S. J. Pharm. Sci. 4(1): 49-52;

4) Haque E and Mohsin ABM. 2009. Intensity of formalin use for consumable fish preservation in Dhaka city, Bangladesh. J. Fish. Int. 4(3): 51-53.

5) The Daily Star, Wednesday, October 17th, 2012, Fight against adulteration.