Is Camphor safe when breathed in?

Camphor is highly flammable, and heating camphor-containing products, such as in a microwave or hot water, can cause splattering, burns, and fire hazards, leading to restrictions on their use.

Why here

Camphor is sometimes heated for steam inhalation, which poses a direct safety risk.

What would have to be true

Heating camphor-containing products in microwaves or adding them to hot water.

Inhaling high concentrations of camphor fumes can irritate the respiratory tract, leading to symptoms such as coughing, wheezing, and shortness of breath, particularly in individuals with pre-existing respiratory conditions like asthma.

Why here

Camphor vapor is commonly inhaled for congestion relief.

What would have to be true

High concentrations of camphor fumes, or using camphor products in ways that generate excessive fumes (e.g., adding to humidifiers, exceeding recommended amounts for steam inhalation).

Inhaling large amounts of camphor can lead to systemic toxicity, manifesting as central nervous system effects including seizures, confusion, lethargy, muscle spasms, and in severe cases, respiratory distress or coma, with children being particularly vulnerable.

Why here

Camphor is readily absorbed through the respiratory tract, and excessive inhalation can lead to toxic systemic levels.

What would have to be true

Inhaling large amounts of camphor vapor, especially from improper use such as adding camphor balms to humidifiers or hot water, or exceeding recommended concentrations for steam inhalation. The neurotoxic dose is reported to be >50 mg/kg body weight.

The use of camphor in dermal leave-on products is restricted by various regulatory bodies regarding concentration, application on broken skin, and use in children.

Why here

Due to potential for irritation and systemic toxicity, regulators have set limits for safe dermal leave-on use.

What would have to be true

Dermal application of products containing camphor above 11% (FDA OTC), above 1% (CIR leave-on), above 3% (Health Canada cosmetics), above 3% (EU leave-on face), or above 5% (EU leave-on body/hair). Also, application to broken skin or use in children under 2 years of age.

Camphor can cause skin irritation, redness, burning, and sensitization, especially on sensitive or damaged skin.

Why here

Direct and prolonged contact with the skin in leave-on products allows for potential irritation and sensitization.

What would have to be true

Dermal application, particularly at concentrations above regulatory limits (e.g., above 1% in leave-on products as per CIR, or above 3-5% as per EU/Health Canada for cosmetics) or on sensitive/broken skin.

Dermal absorption of camphor, especially from high concentrations, large application areas, or broken skin, can lead to systemic toxicity, including central nervous system effects like seizures, confusion, and muscle spasms.

Why here

While generally low, dermal absorption can be significant enough under certain conditions (high concentration, large area, compromised skin barrier) in leave-on products to cause systemic effects.

What would have to be true

Dermal application of high concentrations of camphor, over large body surface areas, or on broken/damaged skin, particularly in vulnerable populations like children.

Camphor crosses the placenta, and while topical exposure hasn't been clearly tied to birth defects in limited data, high-dose or ingested camphor has caused fetal harm, leading to recommendations to avoid use during pregnancy and breastfeeding.

Why here

Dermal absorption, even if low, could potentially expose the fetus or infant, and conservative advice is given due to known risks from other exposure routes.

What would have to be true

Dermal application during pregnancy or breastfeeding, especially on or near the nipple if breastfeeding.