- [Announcer] The personal
protective equipment, PPE, worn by actors in this video was selected based on a risk assessment of the chemicals used in the experiment and conditions simulated in the activity. In scenes where the
presenter did not wear PPE while in the lab, all
chemicals were removed to eliminate chemical hazards. (bright music) - In the previous video of this series, we looked at general strategies for minimizing risks in the lab. In this video, we'll learn
about some specific techniques for minimizing risk when using
chemicals and lab equipment. Minimizing risk is part of a
larger process called RAMP. RAMP stands for recognize
hazards, assess risks, minimize risks, and
prepare for emergencies. For this video, we'll assume
you've already completed the first two steps of RAMP, recognize hazards and assess risks, and also viewed the previous video about strategies to minimize risk. (bright music) There are a wide variety of
lab techniques and behaviors that can minimize the
risk of chemical exposure, personal injury, and property damage. Let's look at some examples. (air whooshing) Messy lab spaces increase
the risk of trips, spills, or using the wrong reagent
during experimental procedures. Put away book bags and other items unrelated
to the experiment. Also make sure your work area is clean. You should periodically step back and examine your workspace. Put away unused glassware and equipment and avoid having containers of unneeded chemicals on the bench. To keep your workspace organized, properly dispose of chemical waste as soon as it is generated and as directed by your instructor. But make sure you don't
discard chemicals you need to use later. When using a lab notebook,
a computer, phone, or calculator in the lab, be sure to keep them away from chemicals that may damage or contaminate them. One way to protect
calculators and phones is to put them in a plastic baggie. Now let's look at two
common lab techniques and how to reduce the
risks associated with them. (bright music) Titrations require the use of glassware such as burettes, pipettes,
beakers, or flasks. When using glassware, be sure to inspect it for star
fractures or hairline cracks. Simply bumping or
heating a flash or beaker with a hairline crack
can cause it to break. Many solutions and solvents
look just like water, so it's important to
temporarily label beakers and flasks while in use. Unmarked containers can cause
confusion, which could lead to you or someone else
mixing the wrong chemicals. A titrate is a solution of known concentration
added to the burette. Pouring from a reagent
bottle can be awkward and increases the risk of a spill. It's best to pour from a small beaker over which you have more control. After estimating how
much titrate is needed, pour about 10% extra
into a labeled beaker. Be careful not to let drips run down the side of the reagent bottle. This can cause a minor spill and also leaves drops on the bottle that the next person might touch. Wipe off any drips and
completely replace the lid. When pouring the titrate into the burette, keep the top of the burette
just below eye level. This makes it easier to
watch the pouring process. Be sure to pour slowly,
especially if using a funnel, to make sure you don't exceed
the volume of the burette. Place a larger beaker under
the tip of the burette to catch any spills. A pipette is often used
to measure a known amount of the solution to be analyzed,
also called the analyte. To safely connect the pipette to the bulb, grasp the pipette close to the end and gently insert it into the bulb. Applying too much force can break the pipette,
- Ow! - Which can result in serious injury. It's important not to place the pipette into the bottle of stock
solution to avoid contamination. Obtain 10% more than
you need in your beaker and pipette from the beaker. Any excess should not go
back into the stock solution, again, to avoid contamination. If you have leftover titrate or analyte, you can offer to share
this with a lab mate. Otherwise, dispose of it in
the proper waste container. (bright music) Chemical synthesis is
another common lab experiment with both chemical and procedural hazards. A common process is to mix
solutions of chemicals, heat and stir the mixture
to produce a precipitate, and isolate the precipitate by filtration. To start a chemical synthesis, you may need to weigh your reagents. Take your reaction flask
and notebook to the balance. Obtain the desired amount of
each solid in small increments. If you get too much at first, put the excess into a waste container to avoid possible contamination
of the original reagent. If you spill any solid at the balance, clean this up immediately and put the spilled solid
into a waste container. Place the weighed solids
into the flask immediately rather than trying to
walk through a crowded lab with the solids on weighing paper. For a reaction in water, heating is usually done on a hot plate. When using any electrical equipment, it's best to check the cord
for frayed connections. Keep the cord off the hot surface and set the hot place on a dry surface. If there's any chance a
hazardous gas will be produced, conduct the reaction in a hood where the gas will be quickly removed. This includes reactions that use a flammable organic solvent too. A properly functioning hood
will minimize the chance that the organic vapor comes in contact with the heat source. Hot glass looks just like cold glass, and a hot iron ring looks
like a cold iron ring. Handle any hot object with
beaker tongs or crucible tongs. These are not interchangeable, and using the wrong tool can
lead to dropping the container, breaking it, or spilling the contents. Sometimes a hot object is best handled by special heat-resistant gloves. Hot beakers or flasks
should only be placed on surfaces that are heat-resistant. Spills of any solids or liquids should be cleaned up immediately. Typically your lab instructor
will take care of this or show you how to do so. (bright music) As noted earlier, at the
end of an experiment, you often have leftover
solids, solvents, or solutions. Share these with lab mates if possible. Somewhere in your lab, there
will be a waste station that has containers
for the various wastes. As noted earlier, it's very
important to put each waste into a properly labeled container. Many lab mishaps have occurred from mixing incompatible chemicals, sometimes leading to explosions. Always close the waste container
after adding your solution. When washing your glassware, be sure not to leave anything in the sink. Broken glassware in the sink
is especially hazardous. Be sure to tell your
instructor if you see this. Wipe your area with a
wet paper towel or sponge and return all equipment
to its proper location. If you're using a Bunsen burner, double-check to make sure
that the gas valve is off. If you use disposable
gloves, remove them correctly and discard as directed
by your instructor. And it's always a good idea to wash your hands when you're done. (bright music) In this video, we covered
some common techniques for minimizing risks in the lab. The key thing to remember is to be mindful of what you and others are
doing in the lab at all times. And before any experiment,
always think about RAMP, recognize hazards, assess risks, minimize risks, and
prepare for emergencies. To learn more about the
other steps in RAMP, be sure to check out the other
five videos in this series. You can find them by clicking here or checking out the
links in the description or visiting acs.org/safetyvideos. - [Speaker] Take one.
(beep) (speaking faintly)
(beep) - Remove them correctly and discard, ugh. Acs.org/videos. I know.
(beep) (beep)