Route(s) of Entry: Inhalation? Yes Skin? Yes Ingestion? Unlikely
Health Hazards:
Acute Effects: Skin contact with wet concrete can dry the skin and cause alkali burns. Within 12 to 48 hours after skin contact (after one to six-hour exposures), first, second, or third degree burns may occur. There may be no obvious pain at the time of exposure. Eye contact with wet unhardened concrete may cause burning and possible corneal edema and blindness. Ingestion of concrete dust may cause esophagus and stomach burns. Person's sensitive to chrome or chromium should not handle wet concrete.
Cutting, grinding, crushing, or drilling hardened concrete or concrete products will generate dust that may contain crystalline silica. Acute effects of exposure to such dust may include:
EYE CONTACT: Direct contact with dust can cause irritation by mechanical abrasion.
SKIN CONTACT: Direct contact can cause irritation by mechanical abrasion.
SKIN ABSORPTION: Not expected to be a significant route of exposure.
INGESTION: Expected to be practically non-toxic. Ingestion of large amounts may cause gastrointestinal irritation and blockage.
INHALATION: Dusts will irritate the nose, throat, and respiratory tract by mechanical abrasion. Coughing, sneezing, and shortness of breath may occur following exposures in excess of recommended exposure limits. However, repeated
overexposures to very high levels of crystalline silica (quartz, cristobalite, tridymite) for periods as short as six months have caused acute silicosis. Acute silicosis is a rapidly progressive, incurable lung disease that is typically fatal. Symptoms include (but are not limited to): shortness of breath, cough, fever, weight loss, and chest pain.
Chronic Effects: Continued exposure of the skin to wet unhardened concrete may cause chronic dermatitis.
Chronic bronchitis may result from chronic exposure to dust generated from cutting, grinding, crushing, or drilling hardened concrete. Chronic exposure to respirable limestone dust in excess of the ACGIH TLV has caused pneumoconiosis (Dusty Lung). Concrete dust may contain more than 0.1% crystalline silica, which is a cancer hazard if inhaled. Cancer risk depends on duration and level of exposure. Prolonged exposure to crystalline silica will cause silicosis, a progressive pneumoconiosis (lung disease). Respirable dust containing newly broken silica particles has been shown to be more hazardous to animals in laboratory tests than respirable dust containing older silica particles of similar size. Respirable silica particles which had aged for sixty days or more showed less lung injury in animals than equal exposures of respirable dust containing newly broken particles of silica.
There are reports in the literature suggesting that excessive crystalline silica exposure may be associated with adverse health effects involving the kidney, scleroderma (thickening of the skin caused by swelling and thickening of fibrous tissue) and other autoimmune disorders. However, this evidence has been obtained primarily from case reports involving individuals working in high exposure situations or those who have already developed silicosis; and therefore, this evidence does not conclusively prove a causal relationship between silica and these adverse health effects. Several studies of persons with silicosis also indicate an increased risk in developing lung cancer, a risk that increases with duration of exposure. Many of these studies of silicosis do not account for lung cancer confounders, especially smoking.
Carcinogenicity: Concrete products are not listed on the NTP, IARC, or OSHA list of carcinogens. However, in October 1996, IARC classified respirable crystalline silica from occupational sources as a known human carcinogen (Group 1). The NTP indicates that crystalline silica is reasonably anticipated to be a carcinogen (Group 2). These classifications are based on sufficient evidence of carcinogenicity in certain experimental animals and on selected epidemiological studies of workers exposed to crystalline silica. Concrete may contain crystalline silica in concentrations greater than 0.1%, principally contributed by the aggregates. Crystalline silica in wet concrete is not respirable and does not pose a hazard when the concrete is in its plastic or unhardened state. Once concrete has hardened, airborne dust generated by grinding, sawing, drilling, breaking, etc. will lead to potentially hazardous exposures to workers and appropriate respiratory protection precautions must be taken.
Iron oxide is listed by IARC as exhibiting evidence of carcinogenicity in experimental animals.
Signs and Symptoms of Exposure: Freshly mixed concrete is irritating to the eyes and skin. It can dry the skin and can cause alkaline burns to the skin and eyes. Hypersensitive individuals may develop an allergic dermatitis.
Chronic exposure to respirable dust containing crystalline silica in excess of applicable OSHA PELs, MSHA PELs, and ACGIH TLVs has caused silicosis, a progressive lung disease. Symptoms of silicosis may include (but are not limited to): shortness of breath, difficulty breathing with or without exertion, coughing, diminished work capacity, diminished chest expansion, reduction of lung volume, right heart enlargement and/or failure. Persons with silicosis have an increased risk of pulmonary tuberculosis infection.
Medical Conditions Generally Aggravated by Exposure
Individuals with chronic respiratory disorders should minimize inhalation of dust generated from cutting, grinding, crushing, or drilling hardened concrete. Individuals with skin diseases should minimize skin contact with the dust, and with wet unhardened concrete.
Physicians Note: Ingestion of large amounts of wet unhardened concrete is unlikely. However, if wet concrete is swallowed, to prevent re-exposing the esophagus and stomach, do not induce emesis or perform gastric lavage. Immediate dilution may prevent esophageal burns. For severe burns, consider esophogoscopy within the first 24 hours. Washing with a pH neutral soap and water may aid in removing hardened concrete from the skin.
Emergency and First Aid Procedures
IWet unhardened concrete or hardened concrete dust in the eyes: Gently lift the eyelids and flush immediately and continuously with flooding amounts of water for a minimum fifteen minutes. Consult a physician immediately if irritation persists or later develops.
IWet unhardened concrete on skin: Quickly remove contaminated clothing. Wash affected areas thoroughly with a pH neutral soap and water. Consult a physician immediately if irritation persists.
Inhalation of hardened concrete dust: Remove exposed person to fresh air and support breathing as needed. Encourage victim to cough, spit out, and blow nose to remove dust. Consult a physician immediately. See physician's note in section III.
