What are the initial symptoms of formaldehyde poisoning?
Nov 24, 2025
Source: Cainiu Health
Dr. Ren Yi
Introduction
Formaldehyde poisoning commonly occurs in newly renovated homes or environments with substandard furniture. Initial symptoms are related to exposure concentration and mainly include respiratory irritation, eye discomfort, skin reactions, neurological abnormalities, and gastrointestinal symptoms. To prevent formaldehyde poisoning, ensure adequate ventilation for 3–6 months after renovation, and consider using activated carbon or indoor plants to help adsorb formaldehyde.
Formaldehyde poisoning commonly occurs in newly renovated homes or environments with substandard furniture. Initial symptoms are related to the level of exposure and mainly include respiratory irritation, eye discomfort, skin reactions, nervous system abnormalities, and gastrointestinal symptoms. A detailed analysis is as follows:
1. Respiratory irritation: This is the most typical early symptom. Formaldehyde irritates the respiratory mucosa, causing dryness and sore throat, coughing—often a persistent dry cough—along with chest tightness and shortness of breath. Symptoms may temporarily improve when breathing fresh air but worsen upon re-exposure to the contaminated environment.
2. Eye discomfort: The eye's mucous membranes are sensitive and easily irritated by formaldehyde. Early signs include dry, itchy eyes, redness and swelling of the eyelids, stinging sensations, and increased tearing. Prolonged exposure may lead to blurred vision. Symptoms gradually resolve over several hours to days after leaving the polluted environment.
3. Skin reactions: After direct skin contact with formaldehyde or inhalation, light red rashes may appear on exposed areas such as the face and arms, accompanied by significant itching. Scratching can exacerbate the condition. Some sensitive individuals may also experience dry, flaky skin.
4. Nervous system abnormalities: Early symptoms often include dizziness and headaches, typically described as a feeling of pressure or fullness. These are accompanied by general fatigue, lethargy, difficulty concentrating, reduced sleep quality, insomnia, or vivid dreams. These symptoms generally improve gradually after leaving the contaminated environment.
5. Gastrointestinal symptoms: Some patients may initially experience mild gastrointestinal disturbances such as nausea and loss of appetite. A minority may have mild abdominal pain or diarrhea. These symptoms are usually mild and easily overlooked, often occurring alongside respiratory or eye symptoms.
To prevent formaldehyde poisoning, ensure adequate ventilation for 3–6 months after renovation. Activated carbon and indoor plants can be used to help adsorb formaldehyde. It is advisable to conduct formaldehyde testing before moving in to ensure levels meet safety standards. Maintaining good indoor air circulation during daily use can reduce the risk of formaldehyde accumulation.
