Wetbench Answers
******Needs modification for UT MBE lab.*******
MANDATORY QUIZ FOR USERS OF WET BENCHES
Why are solvents kept separate from acids and bases?
* To prevent fires and explosions, especially those which would
spray hot acids.How do you recognize an acid wet bench?
* Plastic sink and benchtop.What types of chemicals are allowed at the acid bench? Give 3 examples.
* Acids, bases, and other oxidizers or corrosives. Sulfuric acid (H2SO4),
nitric acid (HNO3), hydrochloric acid (HCl), phosphoric acid (H3PO4),
citric acid, ammonium hydroxide (NH3OH), hydrogen peroxide, ...How do you recognize a solvent wet bench?
* Stainless steel sink and benchtop.What types of chemicals are allowed at the solvent bench? Give 3 examples.
* Methanol (methyl alcohol), isopropanol (2-propanol or isopropyl alcohol),
acetone, tolulene.When something goes down the acid bench sink, where does it go immediately? Point to it. After 5 minutes? eventually?
* Into an acid collection pump, then to the CIS/SNF acid neutralization
system, then to the Palo Alto city sewer.The solvent bench sink is only for secondary confinement. What is secondary confinement?
* It's only there for spills. All chemicals must be collected in
other containers when finished.When something goes down the solvent bench sink, where does it go immediately? Point to it. After 5 minutes? eventually?
* Into a tub under the sink, where it stays until one of us empties it
into an appropriate container for hazardous waste.How do we dispose of our hazardous waste? Fill out a sample tag.
* See tag. Take it to Tony in receiving to have him check it.Where does arsenic-contaminated acids and bases go?
* Must be collected as hazardous waste.Trick question: What does HF feel like when you get it on your skin?
* You generally don't feel anything for 6-12 hours, then
excruciating pain.What does HF do to your skin and body on the long term? Name 3 effects.
* Permanent and painful loss of flesh and skin, permanent bone destruction,
possible death from heart attack or seizures (usu within 12 hours).Let's say I've mixed HF and acetone and poured it down the acid sink. Why would is this bad? Give 3 reasons, each with a possible resulting safety hazard.
* Mixing strong acids with solvents generates heat: fires in the lab.
* HF can't go down the acid bench: cannot be properly neutralized,
possible HF exposure to people, discharge of HF in wastewater. (Any of
these)
* Solvents can't go down the acid bench: explosion throughout the building
when the solvent reaches the mixture from someone else's drain,
especially strong oxidizers like nitric acid.
* Solvents can eat through the acid bench or drain pipes: major acid
spill.What does "flash point of a liquid" mean?
* The temperature at which the vapor *above* the liquid can burn
continuously.Approximately what temperature is the flash point of acetone? (i.e. high, room temperature, cool, below freezing of water, etc.)
* Nineteen degrees below freezing. -19C. (It can explode even in a
freezer!) Any reasonable answer below 0C is okay.Trick question: Where in the lab is it hot enough for acetone vapors to burn?
* Yes, the whole lab!There are 3 fire extinguishers in the lab. Name the locations of two.
* Near the solvent bench, behind System 5, and center cleanroom.There are 3 eyewash stations in the lab. Name two.
* Next to Sys1-2 acid bench, Sys4-5 acid bench, center cleanroom.
There are 4 fire alarm pull stations in the lab. Name two.
* Near the main lab door, near the door behind System 4, center cleanroom,
gowning room.What will happen to your stuff if you leave it unlabeled in the benches?
* It will be given to Darren for safe and legal disposal.