Is Acrolein safe in indoor air?

Acrolein in indoor air is classified as a respiratory irritant and can cause irritation of the eyes, nose, throat, and respiratory tract, as well as tissue damage in the respiratory tract.

Why here

Acrolein is a common indoor air pollutant generated from various indoor sources like cooking with oils, smoking, using gas stoves, and wood-burning fireplaces, leading to direct inhalation exposure.

What would have to be true

Exposure to acrolein in indoor air at concentrations above 0.44 µg/m³ (long-term 24-hour average) or 38 µg/m³ (short-term one-hour average) can lead to adverse respiratory effects and irritation. Studies have reported eye irritation in humans at concentrations as low as 210 µg/m³ and nasal irritation starting at 350 µg/m³.

The International Agency for Research on Cancer (IARC) has classified acrolein as probably carcinogenic to humans (Group 2A), based on sufficient evidence of carcinogenicity in two rodent species and strong mechanistic evidence.

Why here

Acrolein is a prevalent indoor air pollutant, and chronic inhalation exposure is a primary route for the general population.

What would have to be true

Chronic inhalation exposure to acrolein in indoor air.

The other side

The U.S. Environmental Protection Agency (EPA) has concluded that there is not enough information available to determine if acrolein is carcinogenic to humans.

Acrolein is classified by the International Agency for Research on Cancer (IARC) as "probably carcinogenic to humans" (Group 2A) based on sufficient evidence of carcinogenicity in experimental animals and strong mechanistic evidence, although evidence in humans is inadequate.

Why here

Acrolein is a common combustion product found in inhaled air from sources like tobacco smoke, vehicle exhaust, and cooking fumes.

What would have to be true

This classification is based on animal studies where acrolein increased the incidence of malignant neoplasms in mice and benign and malignant neoplasms in rats, and strong mechanistic evidence of carcinogenicity. The U.S. Environmental Protection Agency (EPA) has concluded that there is not enough information available to determine if acrolein is carcinogenic in humans.

Inhalation of acrolein can cause irritation of the eyes, nose, throat, and respiratory tract.

Why here

Acrolein is a common component of indoor and outdoor air, generated from sources like tobacco smoke, cooking, and vehicle exhaust, leading to direct exposure through breathing.

What would have to be true

Eye irritation can occur at concentrations as low as 0.09 ppm (0.21 mg/m³), nasal irritation at 0.26 ppm (0.35 mg/m³), and throat irritation at 0.43 ppm. Respiratory irritation and a decreased breathing rate have been reported at concentrations starting from 0.3 ppm (0.69 mg/m³). Health Canada recommends a short-term (1-hour) exposure limit of 38 µg/m³ (0.017 ppm) to protect against eye irritation.

Long-term or repeated inhalation exposure to acrolein can lead to respiratory tissue damage, increased mucus secretion, inflammation, and can exacerbate asthma symptoms and decrease pulmonary function.

Why here

Acrolein is present in indoor air from various combustion sources and can be inhaled over extended periods.

What would have to be true

Animal studies show effects like increased mucus secretion, inflammation, and cell proliferation in the respiratory epithelium at concentrations as low as 0.9 mg/m³ (900 µg/m³). Epidemiological studies have associated indoor acrolein concentrations (median 0.79 ppb or 0.4 ppb) with self-reported respiratory irritation symptoms and increased asthma prevalence. Health Canada recommends a long-term (24-hour) exposure limit of 0.44 µg/m³ (0.00019 ppm) to protect against adverse respiratory effects.