Corrosives are chemicals that cause rapid destruction of tissue at the site of contact (chemical burns) and are potentially some of the most hazardous chemicals encountered in the laboratory. While acids and bases are the most common corrosives, some oxidizers, dehydrating agents and organics are capable of similar effects. Corrosives can be liquids, solids and gases.
Reactions of corrosives with each other or with organic material create a considerable amount of heat, and potentially cause fire, that may cause burns.
Dilution of acids and bases is exothermic and can cause burns.
- The extent of the injury depends on the type and concentration of the chemical, the route of exposure, the type of tissue contacted, and the speed at which emergency measures are applied.
- Corrosives in the liquid and vapor state are highly irritating to eyes, skin and the respiratory tract. Direct contact can result in rapid visible destruction of tissue, including burning, redness, swelling, and painful blisters.
- Acids are most likely to cause immediate pain upon contact while contact with bases, recognized by the slippery soapy feeling, is less noticeable since pain does not occur immediately.
Corrosive solids and their dusts can damage tissue by dissolving rapidly in moisture on the skin or within the respiratory tract when inhaled.
- Inhalation of corrosives such as fumes, dust, mist or gas cause difficulty breathing and coughing and can lead to pulmonary edema (severe irritation of the lungs resulting in fluid production that prevents the transfer of oxygen to the bloodstream).
- Effects of ingestion range from irritation to severe burns of gastrointestinal tract with nausea, vomiting, diarrhea, convulsion, and possibly death.
- The eyes are the most susceptible with exposure leading to stinging, watering of eyes, swelling of eyelids, intense pain, ulceration of eyes, and potentially loss of eyes or eyesight. Flush eyes immediately with water for at least 15 minutes if exposure occurs.
Handling and Use (Hazard Control)
- Hazard control must focus on efforts to avoid chemical burns by preventing skin and eye contact and to eliminate the potential for inhalation.
- Always work with corrosives in a chemical fume hood to vent any airborne hazards (fumes, gases, vapors, and mists) that are produced during procedures.
- Be aware of the locations of eyewash stations and safety showers before work begins.
- Dilution of acids and bases is exothermic, therefore, always add acids and bases to water. Never add water to acids and bases. Decant down the side of receiving containers to slow mixing.
- Use heat resistant glassware
- Clean up any spills or leaks immediately.
- Wipe drips from containers and bench tops to avoid drying and buildup. Contact with dry residue can result in a burn.
- Always wash hands immediately after using corrosives, even if gloves were worn, and before leaving the lab.
Basic laboratory PPE should be augmented with splash goggles, face shields, and rubber aprons when appropriate, especially when working with large volumes.
- Consult compatibility charts to identify gloves that will resist penetration from the specific corrosive chemicals used.
- Ideally, corrosives are stored in approved corrosive (acid/base) cabinets. When this is not possible, keep them on shelves closest to floor level.
- Acids and bases react with metals which can corrode nonresistant shelving, and other materials in their vicinity.
- Store strong acids and bases separately. Reactions can occur between vapors resulting in the formation of potentially hazardous precipitates on the outsides of bottles and in storage areas.
- Store liquids in secondary containers such as plastic trays to contain leakage.
- Store nitric acid and perchloric acid apart from each other and other corrosives.
- Flammable acids (e.g. acetic acid) should be stored with flammables.