Safety

• Take labeling very seriously. There should never be unlabeled liquid in a fume hood, even for a second. It is very hard to identify a chemical when it has been forgotten (it only takes a second to mix up two beakers). This rule protects our devices, and protects us from accidentally treating dangerous chemicals as if they were used in safe.
• Labels should include your name, full chemical name, date and time.

There are no exceptions to this rule: Never do acid work if you are the only person in the room. You have to have a buddy in the lab. The buddy can be doing something else, but can't leave until you dispose the acid.

When diluting acid, add the acid to the water. Do NOT add water to the acid. If water is poured into concentrated acid, it may react very quickly causing the acid to bubble or boil. This may cause acid to be sprayed over the working area. If acid is added to water, the reaction is dispersed, and if there is a violent reaction it will spray water or dilute acid.

If you spill acid on yourself take off your gear and clothes and rinse off. There is an eye wash by the sink on the opposite side of the room of the acid fume hood. It is on a hose and can be pulled out if you need to rinse off your body and not just your eyes. Do not be shy about removing your clothes or getting water on the floor. It is better that getting an acid burn.

Goggles with a face mask over the goggles

A rubber apron draped over your front

The thin nitrile gloves with the heavier longer gloves over them. The gloves are unlikely to dissolve in the acid, but if the gloves are thin they are prone to tearing allowing acid to attack your hands through an unnoticed hole.

After pouring acid it is a good idea to clean off the bottle with wet towel. This prevents an unsuspecting person from burning themselves if they touch the bottle.

To clean a silicon chip first set up three beakers, one with pure (fuming) nitric acid, and two with rinse water. It is a good idea to use as little acid as possible to minimize the amount of acid you have to dispose of. Place the chip in the nitric acid and let it sit in the beaker for 1 minute. After a minute has passed remove the chip with a pair of metal tweezers and place the chip in the first rinse beaker. After a short time move the chip to the second beaker, then take it out and blow it dry with nitrogen. We use two rinse beakers because the acid is very strong and the residual acid on the chip is enough to make the water in the first beaker acidic.

See Disposing of Chemicals, below.

It is very important to read the Materials Safety Data Sheet (MSDS) before using a chemical. There are carcinogens, respiratory hazards and toxic chemicals in our lab. We maintain a ring binder just outside C5 with all MSDS for chemicals in our lab.

Currently, all chemicals are tracked under the inventory system (with the exception of standard household items such as soaps, adhesive, etc). This means that pretty much everything needs a barcode (with the exception of gases, which have not been added to the system yet).

Procurement

• Chemistry Stockroom: Write barcode number, lab number, and PI name on sales ticket.
• Clark Hall Stockroom: Write barcode number, lab number, and PI name on clipboard.
• Purchase by Procurement Card: Send copy of packing slip which includes PI name and lab number to Vonnie Ellis – 173 S.T. Olin. Vonnie will generate barcode label and send to you. Attach label to chemical container.
• Purchase Order: Send copy which includes PI name and lab number to Vonnie Ellis – 173 S.T. Olin. Vonnie will generate barcode label and send to you. Attach label to chemical container.
• Transfer from Other Clark Hall or Chemistry Group: Contact Vonnie Ellis (x41669 or yme2@cornell.edu) with Barcode Number, PI, and Lab Number.
• Surplus from Outside of Clark Hall: Contact Vonnie Ellis (x41669 or yme2@cornell.edu) with Chemical Name, Unit of Measure, Vendor Name, Catalog Number, PI and Lab Number. Vonnie will generate barcode label and send it to you. Attach label to chemical container.

Disposal

• When disposing of empty bottle, take bar code off and attach to Disposal Sheet
• Return Disposal Sheet at least quarterly to Vonnie Ellis – 173 S.T. Olin
• Obtain additional copies of Disposal Sheets from Clark Hall Stockroom or from Vonnie

Acetone, Ethanol and Isopropanol are all organic solvents. They are collected together in the plastic storage contain labeled “Non-Halogenated Solvents”. The plastic is high density polyethylene. If solvents are halogenated, they get disposed of in the “Halogenated Solvents” disposal in the flammable solvents cabinet.

When a waste container is full, send the slip of paper corresponding to its waste label (usually kept on the top of the flammable solvents cabinet) to the address given on the slip. Make sure to add the date. Get a box for the waste bottle (found in the stock room, on the left-hand side under the counter with the inventory computers). Put the waste container in the box, and place the box next to the door in C5. Replace the chemical waste bottle with a new empty bottle, making sure to remove or cross-out its previous label. Fill out one of the waste label slips, leaving the date empty. Place the label on the new waste container and place duplicate slip on top of the flammable solvents cabinet.

To dispose of acid we neutralize it before pouring it into the waste container. Our containers are made of HDPE and are not rated for fuming nitric acid. They are rated for concentrations of 50% acid or less. But I would still be reluctant to throw the acids away at 50% because when sulphuric acid and nitric acid are mixed they make a strong oxidizing agent and I am not sure how it will react with our container.

To neutralize the acid first dilute the acid into a larger volume of water. Then slowly add Sodium Bicarbonate until the mixture stops bubbling. We first dilute the acid to make the rate of reaction more predictable. Also make sure to use a relatively large beaker to prevent the solution from bubbling over.

If you used a paper towel throw it away into the acid waste bin under the fume hood. If you feel you got a large amount of acid on the towel you can dunk it in a solution of sodium bicarbonate and water before throwing it away.

Rinse out thoroughly. Remove or cross out label. If the bottle has a barcode, adhere to the Clark Hall inventory guidelines above. For large bottles, we typically place these on the floor next to the gas cyllinders in C5 to be later re-used as waste containers.

For more details and for information on obscure chemicals, see the Cornell Environmental Health and Safety Chemical Waste Disposal page.

Moldatherm Insulation

1. Description: White, chalky ceramic insulator in the CVD.
2. Health hazard: Avoid breathing the dust, or contact with skin, eyes, and mouth. Full toxicology is only preliminary, but prolonged respiratory exposure has led to cancer in test animals. At temperatures above 980 C, Moldatherm can partially convert into cristobalite. OSHA limits exposure to cristobalite to 0.05 mg/m^3 of respirable dust. No limit has yet been set for breathing Moldatherm dust.
3. Safety precautions: Use gloves whenever operating the CVD or handling the quartz tubing. Do not touch skin or wipe eyes until after washing hands. If heated above 980 C, a respiratory filter is recommended while in use.
4. The furnace enclosures have been specifically designed to protect us from this hazard by creating a negative-pressure space (effectively a low-flow fume hood). However, you must still be aware of the danger of excess powder. Clean up after yourself, and wash your hands after using the furnaces. Be especially careful when removing the quartz growth tubes, and be sure to wipe them down THOROUGHLY with a WET betawipe before returning them to proper storage. if you notice Moldatherm collecting in the enclosure, vacuum it out using a vacuum cleaner with a HEPA filter (CCMR and the shop have them to borrow) and while wearing a face mask.