Piranha protocol
Piranha solutions are used to remove organic residues from substrates. The traditional piranha solution is a 3:1 mixture of sulfuric acid and 30% hydrogen peroxide. The solution may be mixed before application or directly applied to the material, applying the sulfuric acid first, followed by the peroxide. Piranha solutions, max 2L, are extremely energetic and may result in explosion or skin burns if not handled with extreme caution. You need an instruction for using this fume hood.
Handling
- Only prepare/use piranha in the monolayer lab in the dedicated fume hood as indicated.
- Always use glass (preferably Pyrex) containers. Piranha will melt plastics.
- Mix the solution in a closed hood. Wear gloves and eye protection.
- In preparing a solution involving an acid, always add the acid last. The exception to this rule is Piranha, in which case you add hydrogen peroxide to the sulfuric acid.
- Piranha solution is very energetic and potentially explosive. It is very likely to become hot, more than 100°C. Handle with care.
- Leave the hot piranha solution in an open container until cool. Never store piranha solutions. Piranha stored in a closed container will likely explode.
- Adding any acids or bases to piranha or spraying it with water will accelerate the reaction. This includes Photo resist, which is a strong base.
- Mixing hot piranha with organic compounds may cause an explosion. This includes acetone, photo resist, isopropyl alcohol, and nylon.
- Dispose the piranha via the drain, with copious amounts of water, when finished.
Storage
Do not store piranha. Mix fresh solution for each use. Excess solutions should be disposed via the drain, followed by flushing with copious amounts of water.
Emergency Procedures
- In case of skin contact: May cause skin burns. Call 2222. Flush the skin with copious amounts of water for at least 15 minutes.
- In case of eye contact: Piranha is corrosive and irritating to the eyes. Call 2222. Flush contaminated eye(s) immediately with copious quantities of water for at least 15 minutes.
- In case of inhalation: May irritate the respiratory tract. Call 2222. Conscious persons should be assisted to an area with fresh, uncontaminated air. Seek medical attention in the event of respiratory irritation, cough, or tightness in the chest. Symptoms may be delayed.
- In case of ingestion: Not a likely route of exposure.
Disposal
Do not collect for disposal. After the material has cooled, aspirate excess piranha and dispose via the drain, flushing the drain with copious amounts of water.