Wet Chemistry Safety

From the KNI Lab at Caltech
Revision as of 21:29, 16 February 2023 by Bertm (talk | contribs) (→‎Decanting Chemicals)
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Personal Protective Equipment or PPE Overview

PPE consists of:

  • 1) Acid Resistant Apron (Green) - PUT ON FIRST, Remove Last
  • 2) Face Shield - PUT ON SECOND, Remove Second
  • 3) Trionic E-194 Tripoly Acid Resistant Gloves - PUT ON LAST, Remove First


  • PPE must be worn when using the ACID, BASE, PLATING, and Hydrofluoric "HF" Acid wet benches.
  • Inspect PPE before putting on the safety equipment. Clean if dirty or replace if damaged.
  • Always make sure your workspace and PPE is clean and dry before removing PPE.
  • PPE is not allowed outside of the Wet Chemistry Room. You must remove your PPE before exiting the room.

Acid Resistant Apron (Green) will have a protective flap with the word "INSIDE" written on it. Make sure the word "INSIDE" goes up against your body. Always tie the apron properly so the apron is protecting up to your neck. After removing the apron, fold with the flap marked "INSIDE" is folded in and hang with the outsides facing each other.

Face Shield - always clean the inside of the face shield with IPA and clean room wipe. Adjust the face shield so the shield is secure around your forehead with the knob on the back of the forehead strap. Make sure the face shield does not move from your forehead when looking down. Adjust the shield so you have some room for ventilation and the shield does not move freely using the knobs on each side of the shield.

Trionic E-194 Tripoly Acid Resistant Gloves - always inspect your gloves for damage or cracking due to age before using your gloves. Replace with new gloves if any damage or aging is seen. Write your NAME and DATE on both cuffs when replacing or getting a new pair of Acid Gloves. Store your Acid Gloves over the ACID, BASE or HF bench. Acid Gloves will be disposed if damage is seen or through regular inspection of date (Acid Gloves may be disposed after two week of use).

Hazardous Waste Handling and Labeling

Decanting Chemicals

  • Place a cleanroom wipe with Your NAME, DATE and CHEMICAL being used under the bowl or beaker. Make sure to label any bowls or beakers that contain WATER also. If you are leaving your bowl or beaker over night, include the return date on the cleanroom wipe. Email the safety officer bertm@caltech.edu when leaving any chemicals on the wet bench or hood, if you are unable to return in a timely manor so arrangements can be made to remove the waste.
  • Always cover bowls or beakers when leaving them unattended.
  • Never pour decanted chemicals back into the supply bottle. Once the chemical has been decanted it is considered Hazardous Waste, this is to ensure there is no contamination of our supply chemicals.
  • Check that the work area is clean and dry when finished processing.

Hot Plate Rules

  • When using hot plates, check that your beaker is both suitable for hot plate use and smaller than the area of the hot plate.
  • Never use a Teflon or plastic beaker on a hot plate.
  • Always monitor the temperature of the chemicals on a hot plate with the appropriate thermometer.
  • Never leave your beaker unattended on the hot plate for ANY AMOUNT OF TIME.
  • Hydrofluoric Acid is NEVER allowed on the hot plates.
  • Remover PG and Acetone are the only SOLVENTS allowed to be placed on the hot plate. Temperature must be maintained below 65°C.

Buddy System

The laboratory is open to qualified users both day and night, weekdays and weekends. Certain instruments and procedures may, however, be restricted to the normal work day, or only allowed in the presence of a staff member. In general, a“buddy” is another knowledgeable user within the facility who can and will watch out for you in case of trouble. Laboratory “buddies” must of necessity communicate with each other to be effective. The use of chemicals in particular is restricted to the buddy system after normal hours, i.e. all time outside 8 a.m.-5 p.m. normal workdays.

You may not wet etch, mix chemicals, or dispose of waste without another user in the area. A “visitor” is not considered a knowledgeable user for the purpose of the “buddy” system. The buddy system particularly applies to all wet chemical use during off hours. Additional procedures may apply to specific instruments. You will be advised of these when you are trained on each instrument.

Each piece of equipment will have a training requirement before a user is permitted to use it without supervision. A probationary period of operation, consisting of a minimum of fifteen (15) hours of daytime use without user-caused problems, will then be required before the user will be allowed to operate the equipment off-hours. If a user-caused incident occurs after that, the individual will need to obtain additional training (amount at the discretion of the KNI staff) and repeat the probation on the equipment during daytime hours M-F to re-gain the off-hour privileges.

Secondary Containment

  • Always place ANY chemical stored in GLASS into a red rubber bucket to transfer the chemical from the storage area to the work station.
  • Always use the red rubber bucket to transfer any ACIDS or BASES from the storage area to the work station.
  • Never place any chemical bottles directly onto the floor. Use the red rubber bucket to store the chemical on the floor next to the station when in use. Always return the chemical back to the proper storage area when finished using the chemical.
  • Make sure bottle is clean and dry before placing the bottle into a red rubber bucket or the Satellite Accumulation Area container. This is especially true when removing a hazardous waste bottle from the sinks.

Other Best Practices