How much formaldehyde is in a pear?

In this brief guide, we are going to answer the question “How much formaldehyde is in a pear?”, discuss answers to other related questions like how formaldehyde is metabolized in the body and what are the possible health hazards of formaldehyde intake.

How much formaldehyde is in a pear?

In the pears, you can find 38.7-60 mg/kg of formaldehyde. On average, a 200 grams peer contains 12000 micrograms of naturally occurring formaldehyde.


Formaldehyde is a colorless gas with a strong smell which is most commonly known for its use in building materials and is also a consequence of some environmental pollutants. Living creatures, including humans, also produce formaldehyde through normal metabolic functions. For example, a process called the “one-carbon cycle” uses vitamin folate to enable the synthesis of amino acids and DNA precursors. One byproduct of this process is formaldehyde. 

Similarly, plants and animals (including those that are taken up by humans as food) may produce formaldehyde as part of their metabolic processes.

Why is formaldehyde in food?

Formaldehyde is present in some foods as a natural substance that is produced as a by-product of the processes taking place inside a living organism, whether it is a plant or animal. But, nowadays, many farmers and traders have begun to add synthetic formaldehyde to the foods to make them seem fresher and last longer. 

Many unscrupulous traders have started to spray 37% aqueous solution of formaldehyde, Formalin, on fruits in the past few years. Formalin is known to delay the decomposition of fruits, but the widespread use of formalin, in the preservation of fruits, is posing a threat to public health. This chemical is being used as a solution in water to keep fruits apparently fresh and attractive.

Evn pear seeds are poisonous.

How much formaldehyde can you intake?

As we know that excess of everything is bad so, we need to keep a check on the substances that we intake because they can impose serious hazards to our health. When it comes to formaldehyde intake, there can be side effects as well but these side effects appear at quite high doses. To give perspective, the Agency for Toxic Substance and Disease Registry notes these effects are thought to begin at levels of 50-100 mg/kg/day of ingested formaldehyde. You can compare that to two major estimates of current intake:

  1. For an average adult, the World Health Organization (WHO) estimates the average intake of formaldehyde via food at 1.5-14 mg/day. At the maximum of this range, 0.2 mg/kg of formaldehyde intake by a 150-pound person is well below the levels related to side effects. Most of this formaldehyde should be in a bound or unavailable form. In the United States, the minimal risk level of formaldehyde for humans is considered to be 0.2 mg/kg/day of chronic exposure.
  2. According to the European Food Safety Authority, the formaldehyde intake via food should unlikely exceed 100 mg/day at a maximum level. This amount is still only equal to around 1.5 mg/kg for a 150-pound person.

How formaldehyde is oxidized in the body?

After ingestion, formaldehyde gets absorbed into the blood and disappears rapidly because of its condensation reaction with the DNA, proteins, amino acids, and other amines, as well as by oxidation to carbon dioxide. The rapid oxidation of formaldehyde to formate is known to occur in many tissues including the brain.

Oxidation of formaldehyde is thought to be initiated by the formation of S-formyl glutathione, which is then oxidized by nicotinamide-adenine dinucleotide, and finally cleaved by a thiol esterase releasing formic acid and glutathione.

What are the possible health hazards of formaldehyde intake?

The adverse effects of formaldehyde are due to its high reactivity with amines, and its formation of methylol adducts with nucleic acids, histones, proteins, and amino acids.

Formaldehyde is known for its irritant effects on the mucous membrane due to its reaction with the free amino groups in proteins.

When formaldehyde interacts with proteins and nucleic acids, particularly RNA, tissue fixation and denaturation occurs. The denaturation observed with the DNA is irreversible. So, if permanent cross-links are formed between DNA reactive sites and formaldehyde, these links could interfere with the replication of DNA, as a result of which mutation can occur.

This is why formaldehyde is known to exert mutagenic and carcinogenic effects by both damaging DNA and inhibiting DNA repair.

How to minimize formaldehyde intake?

Formaldehyde is water-soluble so washing the fruits and vegetables under the cold running water is the best measure you can adopt to minimize its intake. Washing the fruits and vegetables is also a good practice from a food safety perspective to help rinse off any dirt or bacterial contamination. 


In this brief guide, we answered the question “How much formaldehyde is in a pear?”, discussed answers to other related questions like how formaldehyde is metabolized in the body and what are the possible health hazards of formaldehyde intake.


Hi, I am Charlotte, I love cooking and in my previous life, I was a chef. I bring some of my experience to the recipes on this hub and answer your food questions.