Wet concrete is a common construction material, but it is not benign. The mixture, which consists of cement, aggregate (like sand or gravel), and water, creates a chemical hazard that can cause serious injury upon contact. Many people do not realize the material is caustic and requires careful handling because it does not feel hot or immediately painful like a thermal burn. Anyone working with or around this material must understand the inherent dangers and treat it as a hazardous substance. Appropriate precautions are necessary to prevent chemical burns and other severe physical harm.
Understanding Concrete’s Chemical Properties
The primary ingredient that makes wet concrete hazardous is Portland cement, the binding agent in the mixture. When water is added to the dry cement powder, a chemical process called hydration begins. This reaction produces calcium hydroxide as a byproduct, a highly alkaline compound. This chemical change dramatically raises the pH level of the wet concrete to a range of 12 to 13, comparable to substances like household bleach or drain cleaner. Since the natural pH of human skin is mildly acidic (around 5.5), contact with the highly alkaline concrete creates a dangerous chemical imbalance, causing a type of injury known as an alkaline burn that progressively damages tissue.
Risks of Skin and Eye Contact
Exposure to wet concrete primarily leads to two types of skin conditions: chemical burns and dermatitis. Chemical burns, often called cement burns, are a form of liquefactive necrosis where the alkaline substance dissolves proteins and fats in the skin. This allows the caustic material to penetrate deeper into the tissue, causing progressive damage that can extend to muscle and even bone in severe cases.
A significant danger is the delayed onset of pain; the burn may not hurt immediately, allowing the material to remain on the skin for hours without the person realizing the extent of the damage. This lack of immediate discomfort means the injury can worsen substantially before a person seeks treatment. Exposure can also cause contact dermatitis (irritant or allergic), as the abrasive nature of the aggregates and the mixture’s tendency to draw water from the skin contribute to this irritation.
Eye contact with wet concrete is extremely dangerous due to the high alkalinity. Splashes or concrete dust mixing with the eye’s moisture can cause severe chemical burns to the delicate tissues. These alkaline burns can lead to serious damage to the cornea and conjunctiva, potentially resulting in permanent vision loss or blindness if not treated immediately.
Emergency First Aid Procedures
Immediate action is necessary following any contact with wet concrete to minimize tissue damage. If wet concrete touches the skin, carefully remove any contaminated clothing, jewelry, or footwear to prevent the substance from remaining trapped against the skin. Avoid touching unexposed areas during this process.
The affected skin area should be flushed immediately with copious amounts of cool, clean water for at least 20 minutes. Continuous rinsing helps to dilute and wash away the alkaline residue. For eye exposure, the eyes must be flushed continuously with clean water for a minimum of 15 minutes while keeping the eyelids open.
After flushing, medical attention must be sought immediately for both skin and eye exposure, especially if a burning sensation persists or the injury appears severe. Do not apply creams, ointments, or lotions, as these can trap the alkaline substance and worsen the injury. Inform medical personnel that the injury is an alkaline chemical burn from concrete, as this type of burn is treated differently than a thermal burn.
Essential Safety Gear and Handling
Preventing contact is the most effective way to avoid injury when working with wet concrete. Personal Protective Equipment (PPE) provides a necessary barrier against the caustic material. Workers must wear the following:
- Waterproof, alkali-resistant gloves.
- Long-sleeved shirts and full-length pants to cover all exposed skin.
- Waterproof boots high enough to prevent concrete from entering, especially when standing in the mixture.
- Safety goggles that seal around the eyes to protect against splashes and dust.
Safe handling practices include minimizing splashing during placement and avoiding kneeling directly on wet concrete without waterproof knee pads. Any saturated PPE should be replaced immediately, as the fabric can transmit the alkaline effects to the skin.