Sodium percarbonate (SPC) is a white, crystalline solid commonly used in “oxygen bleach” and laundry booster formulations. While SPC is generally considered safe for household use when diluted according to instructions, the concentrated powder does present specific toxicity risks that consumers should understand. These risks arise from the chemical reaction that occurs when the powder contacts water or the body’s moisture, creating a highly alkaline and corrosive solution.
How Sodium Percarbonate Works
Sodium percarbonate is chemically categorized as an adduct, a stable combination of sodium carbonate and hydrogen peroxide. This structure allows the active bleaching agent, hydrogen peroxide, to be stored safely in a solid, powdered form. When the powder is dissolved in water, the adduct dissociates into its two components: sodium carbonate (soda ash) and hydrogen peroxide. The resulting solution is highly alkaline due to the sodium carbonate, typically registering a pH around 10.5 in a 1% solution. This alkalinity helps to loosen dirt and grease. The core cleaning power comes from the hydrogen peroxide, which further decomposes to release oxygen atoms. This oxidation process breaks down stains, brightens fabrics, and acts as a disinfectant.
Health Effects of Exposure
The toxicity profile of concentrated sodium percarbonate is directly related to its decomposition products: the corrosive nature of the alkaline solution and the oxidizing power of the released hydrogen peroxide. Acute exposure to the concentrated powder can cause significant local damage to tissues. The high pH of the solution formed upon contact with moisture in the body is the primary driver of these corrosive effects.
Accidental ingestion of the powder constitutes a serious health hazard. Once swallowed, the compound rapidly dissolves in the moist environment of the gastrointestinal tract, releasing corrosive hydrogen peroxide and alkaline sodium carbonate. This can lead to severe gastrointestinal upset, abdominal pain, vomiting, and diarrhea. In extreme cases, it may cause tissue burns or perforations in the esophagus and stomach.
Direct contact with the concentrated powder or a strong solution can cause irritation to the skin and eyes. While brief skin contact may result in only mild irritation, prolonged or repeated exposure can lead to redness and chemical burns. The effects on the eyes are particularly severe; contact with the powder can cause serious eye damage, including corneal burns and potentially irreversible injury.
Inhalation of the fine dust particles can irritate the mucous membranes of the respiratory tract. When the powder is aerosolized, breathing it in may cause coughing and difficulty breathing. This respiratory irritation is a result of the dust reacting with moisture in the airways, causing a localized chemical burn.
Safe Handling and Storage
Minimizing the risk of exposure requires strict adherence to preventative measures during both handling and storage of the concentrated product. When working with the dry powder, always wear personal protective equipment, including safety glasses or goggles and impervious gloves, to shield the eyes and skin from direct contact. Ensure the work area is well-ventilated to prevent the inhalation of any airborne dust.
Careful handling should focus on preventing the generation of dust and avoiding contamination. Wash hands thoroughly before and after use. The powder should be stored in a cool, dry, and well-ventilated location, away from direct sunlight or heat sources, as heat can accelerate its decomposition.
Proper storage also means keeping the container tightly closed and protected from moisture, which can trigger the chemical reaction prematurely. Sodium percarbonate is an oxidizer and must be stored away from incompatible materials, such as acids, strong bases, organic substances, and combustible materials, to prevent hazardous exothermic reactions or fire. Containers should always be kept out of the reach of children and pets.
Emergency Response
In the event of accidental exposure, immediate action is necessary. If the powder or a strong solution contacts the skin, immediately remove any contaminated clothing and wash the affected area thoroughly with mild soap and large amounts of water. Seek medical advice if irritation, pain, or redness persists after washing.
Should the powder or solution get into the eyes, flush them immediately and continuously with water for at least 15 minutes. It is important to hold the eyelids open during the rinsing process and to remove contact lenses, if present, to ensure all areas are flushed. Immediate medical attention is necessary due to the risk of serious eye damage.
In case of accidental ingestion, rinse the victim’s mouth with water, provided they are conscious. Do not attempt to induce vomiting, as this can cause further corrosive damage to the esophagus. It is crucial to seek immediate medical attention or contact a Poison Control Center right away. If dust is inhaled, move the person to fresh air and keep them comfortable while seeking medical advice if they experience respiratory symptoms.