Overview

Do not pour water into concentrated acids or bases. Slowly add the acid or base to the water while stirring.

Diluting Acids or Bases

Be aware that the solution may heat up when mixing corrosives (particularly acids and bases) with other chemicals and use appropriate cooling methods, as needed. If you must neutralize a solution as part of your procedure, add the neutralizing agent slowly and with stirring

Neutralizing Acids or Bases

Storage

Segregate incompatible chemicals and use secondary containment. Follow any substance-specific storage guidance provided in SDS. Corrosives should not be stored above eye level.

Corrosive Storage

Handling

Use a properly functioning chemical fume hood when handling corrosive materials, especially those that can form mists/vapors upon contact with air, often referred to as “fuming” (this includes many strong acids and bases).

Handling Corrosives

Contamination

Never use pipette tips or plastic serological pipettes to transfer solvents from your stock solvent bottles.
Preferably pour the solvent to a clan bottle or measuring cylinder. Glass serological pipets and transfer pipets are ok to use.

Plasticizers from Pipette Tips

Never use pipette tips to transfer concentrated acids, always use glass pipettes or glass syringes with stainless steel needles (rinse the syringe immediately after transferring with LCMS grade water). For larger quantities we use disposable glass pipets. Once the solvents are transferred to a smaller bottle and for diluted acid solutions (<5%) it is ok to use pipette tips. Replace those working solvents and solutions regularly; you can use the same bottle for the same solvent over and over, just rinse it a little bit before your new solution.

Plasticizers from Pipette Tips

Concentrated Solutions of Acids and Bases

Corrosive acids and bases are common wastes generated in laboratories on campus. Corrosivity is the only hazardous waste characteristic that may be treated by a generator onsite without an EPA permit.

Generators of corrosive wastes which have no other hazardous characteristics should neutralize the wastes to a stabilized pH between 5.5 and 9.5. The neutralized non-hazardous waste may then be drain disposed followed with a water flush (20 parts of water).

Procedures for neutralizing acids and bases are described in the following three sections. Note: Neutralization is recommended only for very small volumes of corrosive acids and bases. You should only perform neutralization of corrosives if you have been trained, you feel confident that you understand the process, you have the proper personal protective equipment, and are comfortable doing it.

General Neutralization Procedures

• Do neutralizations in a fume hood behind a safety shield, as vapors and heat may be generated. Wear lab coat or apron, gloves and goggles. A face shield in combination with safety goggles is recommended. Please note, a face shield alone is not sufficient, safety goggles must be worn when using a face shield.
• Keep containers cool during process, such as placing a beaker in a bucket with slushy ice.
• Work slowly.
• After neutralization is complete, dispose of down the drain followed by 20 parts water to the neutralized solution.
• Follow the specific neutralization procedures below for the acid or base you are trying to neutralize.

Acid Neutralization

While stirring, add acids to large amounts of an ice water solution (1:10) of base such as sodium carbonate, calcium hydroxide, or sodium hydroxide for concentrated acids.

• When a pH of at least 5.5 to 9.0 is achieved, dispose of the solution down the drain followed by 20 parts water to the neutralized solution.

Base Neutralization

• Add the base to a large vessel containing water (1:10). Slowly add a 1M solution of Hydrochloric acid.
• When a pH of 5.5 to 9.0 is achieved, dispose of solution down the drain followed by 20 parts water to the neutralized solution.