Is Formaldehyde Harmful to Humans?

by Kate Onissiphorou

While formaldehyde is typically safe at very low levels, it’s highly toxic and harmful at concentrations above 100 ppm. Even at a concentration of 50 ppm, formaldehyde can cause potentially life-threatening health issues including a severe pulmonary reaction.

Formaldehyde has a range of industrial applications. For example, it’s often used as a chemical precursor to other more complex organic compounds such as urea-formaldehyde resin. It’s also used to preserve biological tissue during embalming and sample preservation.

What is formaldehyde?

Formaldehyde is a colourless organic compound with the chemical formula CH₂O. It’s the simplest form of aldehyde and, like other aldehydes, it has a terminal carbonyl functional group.  A Graphic showing key information on formaldehyde

Formaldehyde occurs naturally as an intermediate byproduct of the reaction between methane and oxygen. It’s produced through burning organic compounds, such as in the case of fossil fuels and forest wildfires. The compound can also be detected in human blood as a byproduct of the metabolism of the amino acids serine and threonine. That said, about 90% of the formaldehyde in the environment is actually formed in the upper atmosphere.

In pure form, formaldehyde exists as a pungent-smelling colourless gas. However, due to its instability in a gaseous phase, the compound is normally dissolved in water for storage purposes. 

Formaldehyde is typically distributed as a 37% aqueous solution for commercial purposes. At 10% concentration it’s called formalin, a product commonly used as a disinfectant and preservative agent for biological specimens. Frog preserved in formaldehyde in a glass jar

What food is formaldehyde used in?

As a byproduct of metabolism, formaldehyde can be found in many foods, including:

  • Fruits, such as apples, bananas, grapes, and plums
  • Veg, such as onions, carrots, and spinach
  • Seafood
  • Beef
  • Poultry

Naturally-occurring formaldehyde in food is typically safe because of its low concentration (it’s commonly present at levels between 300 and 400 mg/kg). In some cases, the compound is artificially added as a preservative in seafood.

Is formaldehyde toxic?

Just like other chemicals, formaldehyde has a toxicity level. It’s highly toxic and becomes a threat to human life at a concentration of 100 ppm. Even at a relatively low concentration of 50 ppm, it can cause several health issues, such as severe pulmonary reactions, in a matter of minutes. 

Formaldehyde acts as a systemic poison that’s typically absorbed by the body through inhalation. Anyone exposed to it may suffer from lung irritation and pulmonary oedema, which may in some cases lead to pneumonia. Severe bronchial irritation can be fatal. Read on to learn more about the effects of formaldehyde on the body.

What does formaldehyde do to the body?

As a strong irritant to living biological tissues, formaldehyde can cause irritation and chemical burns. If it’s inhaled or comes into direct contact with human tissue it can cause the following:

  • Severe respiratory tract irritation
  • Skin irritation
  • Dizziness
  • Suffocation
  • Severe eye and skin burns

When inhaled at low concentrations for a short period, formaldehyde can irritate the nose and throat. Exposure to high concentrations can cause coughing, choking and even death. A graphic showing the affects formaldehyde has on the body

Is formaldehyde flammable?

Pure formaldehyde is highly flammable in gas form as it can easily polymerise in an exothermic reaction. This is why it’s usually dissolved in water when handled for commercial purposes. 

Even as a liquid, the vapour from the aqueous solution can still ignite when exposed to high heat or flame. Formaldehyde should therefore be stored in a cool facility to prevent possible explosions or fire.

Reducing exposure to formaldehyde

As formaldehyde can be found in smoke, food, and some household products, you might want to consider the following preventative measures to reduce the risk of exposure:

  • Ban smoking indoors
  • Air new furniture before use
  • Have proper indoor ventilation
  • Wash permanent press clothing before wearing them

Are you a business requiring formaldehyde? Visit our online shop to buy top-grade formaldehyde from one of the UK’s most trusted chemical manufacturers.


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