Formaldehyde Is Everywhere Indoors — How Can We Create Healthier Living Spaces?

Formaldehyde, a colorless and odorless gas, is widely recognized as one of the most significant chemical pollutants contributing to Sick Building Syndrome (SBS). Often unnoticed, it can be found in modern indoor environments such as residences, offices, hotels, restaurants, and retail spaces. Due to its widespread sources, prolonged emission period, and potential health risks, formaldehyde has become a growing concern in indoor environmental quality. 

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I. Where Does Formaldehyde Come From?

Formaldehyde is commonly present in a wide range of interior materials, including engineered wood products, furniture, paints, wall coverings, coatings, and adhesives. At room temperature, residual formaldehyde in these materials can continuously off-gas into the indoor environment over time.

It can enter the human body through the respiratory system and skin contact, posing a long-term exposure risk. The issue is further exacerbated in poorly ventilated spaces. In tropical regions without adequate airflow, or in colder climates during heating seasons, formaldehyde concentrations can accumulate rapidly in enclosed indoor environments.

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The International Agency for Research on Cancer (IARC) classifies formaldehyde as a Group 1 carcinogen, with sufficient evidence linking it to nasopharyngeal and sinonasal cancers, and limited evidence suggesting a possible association with leukemia.

The World Health Organization (WHO) identifies formaldehyde as a major indoor air pollutant and recommends exposure limits of:

· 0.1 mg/m³ (0.08 ppm) for short-term (30-minute) exposure

· 0.08 mg/m³ (0.065 ppm) for long-term exposure

II. Health Hazards of Formaldehyde

1. Sensory Irritation

When indoor formaldehyde levels exceed 0.1 mg/m³, individuals may experience eye irritation, tearing, sore throat, coughing, and chest discomfort.

2. Neurological and Immune Effects

Long-term exposure may lead to symptoms such as headaches, fatigue, sleep disturbances, reduced concentration, and decreased overall well-being. It may also weaken the immune system function, increasing susceptibility to infections.

3. Carcinogenic Risks

· Nasopharyngeal cancer: Strong evidence links occupational exposure to elevated risk

· Leukemia: Particularly myeloid leukemia, potentially due to effects on blood-forming cells

III. Case Study

According to monitoring conducted by the Chinese Research Academy of Environmental Sciences, in newly renovated environments with excessive formaldehyde levels, the incidence of abnormal blood pressure fluctuations and cardiac arrhythmias was found to be 2.3 times higher than in standard indoor environments.

For individuals with pre-existing cardiovascular conditions, poor indoor air quality may act as a significant environmental trigger.

In 2018, an investigation by the Australian Broadcasting Corporation (ABC) program Four Corners highlighted severe indoor air quality issues in Sydney’s King Street Tower. Several long-term occupants developed serious illnesses, including leukemia and lymphoma. Investigations suggested that pollutants originated from building materials, ventilation systems, and external contamination sources such as vehicle emissions.

This case highlights that even premium-grade buildings may face substantial indoor air quality challenges.

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IV. Treatment Using the Singrass® Indoor Smart Eco System (ISES™)

The Singrass® Indoor Smart Eco System (ISES™) utilizes planted communities of leafy vegetables to effectively bring the Singapore Botanic Gardens into every high-rise building.

Why can “vegetable plants” improve indoor environments?

1. Living Air Purifiers

Empirical measurements have shown that leafy vegetables such as kale, lettuce, and basil can absorb, transform, and degrade CO₂, formaldehyde, and TVOCs in the air. Singrass® tests indicate that formaldehyde levels decreased by approximately 90% in an office four months after installing the ISES™.

2. Humidity Regulation and Comfort

Through natural transpiration, plants help regulate indoor humidity levels, reducing dryness caused by air conditioning or heating systems and improving overall comfort for occupants.

3. Edible and Sustainable

The ISES™ system incorporates hydroponically grown, pesticide-free leafy vegetables that are both functional and harvestable. This creates a unique integration of sustainability, wellness, and everyday usability.

By combining aesthetics, ecological functionality, and practical value, Singrass® transforms greenery from a decorative element into an active component of indoor living environments.

Photo taken in Shenzhen, China

V. Looking Ahead: A Greener Indoor Future

Formaldehyde emissions from indoor materials can persist for 10 to 15 years, making it a long-term environmental challenge. No single solution can completely eliminate the issue, and consistent ventilation remains essential.

Traditionally, solutions such as fresh air systems, air purifiers, and chemical treatments have been used to improve indoor air quality. Today, Singrass® introduces a nature-based approach—leveraging ecological systems to reconnect indoor spaces with living environments.

The future of indoor spaces lies in integrating sustainability, health, and design. Creating healthier environments is no longer optional—it is a responsibility shared by all.