A corrosive chemical destroys or damages living tissue by direct contact. Some acids, bases, dehydrating agents, oxidizing agents, and organics are corrosives.
Examples of Corrosives
Examples of acidic corrosives include the following:
- Hydrochloric acid
- Sulfuric acid
- Perchloric acid
- hydrofluoric acid (also health hazard due to fluoride ion)
Examples of alkaline corrosives include the following:
- Sodium hydroxide (lye)
- Potassium hydroxide
Examples of corrosive dehydrating agents include the following:
- Phosphorous pentoxide
- Calcium oxide
Examples of corrosive oxidizing agents include the following:
- Halogen gases
- Perchloric acid
Examples of organic corrosives include the following:
- Acetic acid
Concentrated acids can cause painful burns that are often superficial. Inorganic hydroxides, however, can cause serious damage to skin tissues because a protective protein layer does not form. Even a dilute solution such as sodium or potassium hydroxide can saponify fat and attack skin. At first, skin contact with phenol may not be painful, but the exposed area may turn white due to the severe burn. Systemic poisoning may also result from dermal exposure.
Safe Handling Guidelines for Corrosives
To ensure safe handling of corrosives, the following special handling procedures should be used:
- Always store corrosives properly. Refer to the MSDSs and the Chemical Storage section of this manual for more information.
- Always wear gloves and face and eye protection when working with corrosives. Wear other personal protective equipment, as appropriate.
- To dilute acids, add the acid to the water, not the water to the acid.
- Corrosives, especially inorganic bases (e.g., sodium hydroxide), may be very slippery; handle these chemicals with care and clean any spills, leaks, or dribbles immediately.
- Use a chemical fume hood when handling fuming acids or volatile irritants (e.g., ammonium hydroxide).
- A continuous flow eye wash station should be in every work area where corrosives are present. An emergency shower should also be within 100 feet of the area.
Corrosive Example: Perchloric Acid
Perchloric acid is a corrosive oxidizer that can be dangerously reactive. At elevated temperatures, it is a strong oxidizing agent and a strong dehydrating reagent. Perchloric acid reacts violently with organic materials. When combined with combustible material, heated perchloric acid may cause a fire or explosion. Cold perchloric acid at less than 70% concentration is not a very strong oxidizer, but its oxidizing strength increases significantly at concentrations higher than 70%. Anhydrous perchloric acid (>85%) is very unstable and can decompose spontaneously and violently.
If possible, purchase 60% perchloric acid instead of a more concentrated grade. Always wear gloves and goggles while using perchloric acid. Be thoroughly familiar with the special hazards associated with perchloric acid before using it.
Heated digestions with perchloric acid require a special fume hood with a wash-down system. The vapors can form crystals on the hood interior that are explosive.
Corrosive Example: Hydrofluoric Acid
HF is one of the most dangerous common reagents that we use in a laboratory environment. Exposures of only 2% of the body to concentrated HF can lead to death, and it is also lethal at a concentration of 50 ppm in air. Fluoride ions bind rapidly to electrolytic ions in your tissues, such as Ca+2, causing severe electrolyte imbalance. Death can occur in as little as 30 minutes. Death is usually from massive organ failure (heart failure, etc.). If you do not die quickly you will develop severe burns and excruciating pain. The idea that HF primarily affects your bones is a common misunderstanding, bone problems only develop if you survive.
There are several ways to help prevent hydrofluoric acid accidents from occurring in the first place. Never use hydrofluoric acid when working solo or after hours. HF may be used when working alone during regular working hours provided knowledgeable personnel have been alerted and at least one is in the general vicinity.
- All personnel, not just those who will be using hydrofluoric acid, should be informed of the dangers of this chemical and the emergency procedures necessary in case of an accident.
- All persons who will be using HF must be made aware of its properties and trained in proper procedures for use and disposal.
- Companies/Laboratories which keep or use HF gas or concentrated solutions (>1% hydrofluoric acid) should have these emergency procedures on hand as well as an MSDS.
- Undergraduate students should never be given the task of mixing HF solutions. Only experienced persons familiar with its properties should handle the concentrated acid.
- A small supply of calcium carbonate or calcium hydroxide should be kept near where the work will be conducted. If a small quantity (100 ml or less) of dilute HF solution is spilled, clean it up by using powdered calcium carbonate or calcium hydroxide. A commercial hydrofluoric acid spill kit can also be used.
- If a large amount is spilled, or the HF is concentrated, contain the spill as best as can, evacuate the area, and call 911. Avoid exposure to the vapors.
- Dispose of unwanted hydrofluoric acid by contacting RMSO.
- When working with hydrofluoric acid or concentrated HF solutions (> 1%):
- Wear goggles and a face shield. Wear a long-sleeved, buttoned lab coat, pants or long skirt, and closed-toe shoes. Wear Neoprene or Nitrile (22mil) gloves or other hydrofluoric acid resistant gloves (HF burns around the fingernails are extremely painful, difficult to treat, and may require surgical removal of the nail). A chemical resistant apron is also recommended.
- Make sure to have a tube of HF "antidote" Calcium gluconate gel on hand in case HF comes into contact with the user’s skin.
- Calcium gluconate gel has a shelf life stamped on the tube. Replace prior to expiration.
- Wash skin with soap and water then dry and immediately apply the calcium gluconate gel. Repeat application every 5-10 minutes for several rounds.
- Any person exposed to HF must seek immediate medical assistance.
Please contact RMSO for further assistance is you plan to use HF or have need for disposal of HF solutions.
Revised November 2014