SECTION 2E: Corrosives

• Chemicals
• Hydrofluoric Acid
• Phenol

Chemicals (top)

Many chemicals commonly used in the laboratory are corrosive or irritating to body tissue. They present a hazard to the eyes and skin by direct contact, to the respiratory tract by inhalation or to the gastrointestinal system by ingestion.

Corrosive Liquids (e.g. mineral acids, alkali solutions and some oxidizers) represent a very significant hazard because skin or eye contact can readily occur from splashes and their effect on human tissue generally takes place very rapidly.  Bromine, sodium hydroxide, sulfuric acid and hydrogen peroxide are examples of highly corrosive liquids.  Keep in mind the concentration of the chemical directly affects its corrosive properties.  Vinegar and glacial acetic acid are chemically identical.  Both are solutions of acetic acid, vinegar-7%, glacial acetic acid-100%.  Vinegar is found in salad dressing, whereas glacial acetic acid is very corrosive to human tissue and can even be ignited.

The following should be considered:

1. The eyes are particularly vulnerable. It is therefore essential that eye and face protection be worn in all laboratories where corrosive chemicals are handled.
   
2. Gloves and other chemically resistant protective clothing should be worn to protect against skin contact.
   
3. To avoid a flash steam explosion due to the large amount of heat evolved, always add acids or bases to water (and not the reverse).
   
4. Acids and bases should be segregated for storage.
   
5. Liquid corrosives should be stored below eye level.
   
6. Adequate quantities of spill control materials should be readily available. Specialized spill kits for acids and bases are available through most chemical and laboratory safety supply catalogs.

Corrosive Gases and Vapors are hazardous to all parts of the body; certain organs (e.g. the eyes and the respiratory tract) are particularly sensitive. The magnitude of the effect is related to the solubility of the material in the body fluids. Highly soluble gases (e.g. ammonia, hydrogen chloride) cause severe nose and throat irritation, while substances of lower solubility (e.g. nitrogen dioxide, phosgene, sulfur dioxide) can penetrate deep into the lungs.

1. Warning properties such as odor or eye, nose or respiratory tract irritation may be inadequate with some substances. Therefore, they should not be relied upon as a warning of overexposure.
   
2. Perform manipulations of materials that pose an inhalation hazard in a chemical fume hood to control exposure or wear appropriate respiratory protection.
   
3. Protect all exposed skin surfaces from contact with corrosive or irritating gases and vapors.

Hydrofluoric Acid (top)

Hydrofluoric acid is particularly dangerous, since skin or eye contact with liquid or vapors may result in deep, painful, slow-healing burns. Burns from dilute solutions (< 50% HF) may not become apparent for several hours after contact. Hydrofluoric acid readily penetrates the skin, allowing the fluoride ion to destroy soft tissue and decalcify bone. Inhalation of hydrofluoric acid gas or vapor can seriously damage lungs and may be fatal.

In the event of hydrofluoric acid exposure to skin or eyes, immediately rinse with water for 5 minutes and apply calcium gluconate gel. If no gel is available, continue rinsing for 15 minutes. In both cases, seek medical attention. If hydrofluoric acid is ingested or inhaled, call 911 immediately for medical attention.

Calcium gluconate gel has a shelf life of approximately two years.  Tubes of gel for your laboratory can be purchased directly from EHS.

Hydrofluoric acid reacts with glass, ceramics and some metals.  Solutions should be stored in high-density polyethylene containers.

Spills of hydrofluoric acid may be soaked up with compatible spill pillows such as PowerSorb® or PolySorb®.  Note that many spill pillows (e.g., Hazorb®, Chemsorb®) cannot be used for hydrofluoric acid.  Be sure to have appropriate spill control materials available in sufficient quantity.

Phenol (top)

Phenol is commonly used in many laboratories at Princeton. It is irritating to the skin, eyes and respiratory tract, but has a local anesthetic effect, so that no pain may be felt on initial contact. Normally, skin contact will result in whitening of the skin, which may later develop into severe burns.

Phenol is also rapidly absorbed through the skin, and toxic or even fatal amounts can be absorbed through relatively small areas. Exposure to phenol vapor from any route may cause nausea, vomiting, muscle weakness and coma. Eye exposure may lead to blindness.

In the event of skin exposure to concentrations of 10% or more phenol, flush with water for 15 minutes or until the affected area turns from white to pink.  Apply a solution of 400 molecular weight polyethylene glycol, if available.  Do not use ethanol.  Seek medical attention.  Alert medical personnel that skin exposure is a significant route for systemic exposure.

 

Section 2d Section 2f