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Jan 21, 2010

Setting Up a Home Lab Part I





As is true of most hobbies and other organized activities, if you're going to do home science it's desirable to have a dedicated place to do it. But dedicated lab space is by no means essential. After all, when most people think of home science the image that comes to mind is a kid working with a chemistry set at the kitchen table. Even if the kitchen table is the only available place to work, you can get a lot of home science done.



But before you settle on the kitchen table, give serious consideration to other possible locations for your home lab. Of course, you may have to choose between using the kitchen table and having no lab at all. In that case, do the best you can with what you have to work with. Here are some things to think about when you choose a location for your home lab.
Counter space
Even microscale experiments require a surprisingly large amount of workspace. In addition to space for the experiment setup itself, you'll need space for your balance, your microscope and supplies, your lab notebook, temporary space for any chemicals that you are using, and so on. Consider 10 square feet (1 square meter) of counter or table space as an absolute minimum, and more is better. The ideal setup is arranged like a photographic darkroom or galley kitchen, with a wet side and a dry side. The wet side is used for doing the actual experiments, and the dry side for storing and weighing chemicals, recording observations in your lab notebook, and so on.


Protecting Work Surfaces


Some of the chemicals you work with may stain or otherwise damage wooden or laminate work surfaces. We protect our work surfaces, which are standard kitchen laminate counters, by covering them with rubber non-slip mats that are available in various sizes and thicknesses at craft stores. We also put an old bath towel between the counter top and the rubber mat. The mat provides a smooth, level, chemically-resistant work surface, and the old towel absorbs any liquids that run off the mats.

Our advisor Dr. Mary Chervenak is an expert on paints and coatings. We asked her and another advisor, Dr. Paul Jones, if there was any kind of paint that could be used to protect surfaces from most laboratory chemicals. The short answer is "not really." Standard latex, polyurethane, and epoxy-based paints and coatings offer reasonably good protection against many reagents and solvents, including the dilute reagents used in most of the experiments in this book. However, they offer less (or no) protection against strong acids or bases or some organic solvents.

Still, as Dr. Jones commented, some protection is better than none, and in a sense you can think of these paints as ablative coatings. The coating itself may dissolve in or be eaten away by a strong chemical, but it may protect the underlying surface long enough for you to dilute, mop up, or neutralize the spill. If we used a wooden workbench or a similar surface, we'd put several thick coats of an epoxy-based deck or floor paint on it, and then protect it further with a rubber mat and towel.

Even if you take reasonable precautions and work carefully, it's almost inevitable that at some point you'll spill something nasty on your work surface. That's a good argument for choosing a work surface that's expendable. If you eat holes in a sheet of plywood or particle board, that's cheap and easy to replace. If you eat holes in your washer/drier, you may have some explaining to do.





Storage
It's important to have secure storage space for your equipment and chemicals--particularly those chemicals that are toxic, flammable, or otherwise hazardous--and that your lab storage space not be shared with general household items, particularly food and beverages. Make absolutely certain that children and pets cannot get to dangerous equipment and chemicals. If you have only part-time possession of your work area, store your equipment and chemicals in Rubbermaid tubs or similar containers, under lock and key if possible.

Segregate toxic, flammable, reactive, and corrosive chemicals into separate containers or cabinets according to their storage color codes. Gladware, Tupperware, or Rubbermaid kitchen storage containers are available in various sizes, are made of chemical-resistant plastic, and have sealable lids. They're an excellent choice for segregating your chemicals by type. You can also use heavy zippable plastic freezer bags to isolate individual chemicals or compatible groups of chemicals within a larger storage container. (Yes, Figure 1 shows some extremely toxic chemicals, which I purchased while I was working on the home forensics book.)


Separate Labs

If at all possible, keep your microscope and its supplies in a work area separate from where you do wet chemistry. For example, our main lab is in the basement, but our microscope is set up on a second desk in my office upstairs.


Ventilation
Some experiments produce smoke, strong odors, or even toxic fumes. It's important to have some means of ventilating the work area and exhausting these fumes to the outdoors. The ideal solution is a formal laboratory exhaust hood, but an open window with a portable exhaust fan can often serve the purpose. For experiments that produce a lot of smoke or fumes, work outdoors.
Lighting
It's dangerous to work in a poorly-lit environment. As a teenager, my first home lab was located in a dark corner of the basement, and I had more than one near-accident before I installed some fluorescent fixtures. Make sure your work area is well lit. If the overhead lighting is inadequate or nonexistent, use table lamps, clamp lamps, or other portable light sources.
Electric receptacles
You can get along without electricity other than for lighting, but it's very convenient to have one or more electric receptacles within easy reach of your work surface. If those receptacles are not protected, install ground-fault circuit interrupters.
Water and sewer
Although it is not essential, it is extremely convenient for the home lab to have access to running water and a sewer connection. If that's not possible, acquire a large bottle to use as a water supply. The 5-gallon plastic carboys used in water coolers are ideal, but you can substitute recycled 2-liter soda bottles. With a stopper, some tubing, and a pinchclamp, you can build a siphon to deliver water as needed. Use a large plastic bucket, tub, or similar container for waste liquids, and empty it after each lab session.
Flooring
Even if you are extremely careful, sooner or later you are bound to spill something. Murphy's Law says that what you spill will be corrosive or strongly colored, and will fall exactly where you don't want it to fall. If the floor is carpet or another vulnerable material, your spouse, parents, or significant other will not be amused. Sheet vinyl or linoleum is the best flooring material for a home lab, although vitreous tile and similar resilient materials are also good. If the floor is concrete, consider painting it with epoxy-based floor paint to prevent it from being stained or absorbing spilled chemicals.
We have a seldom-used second kitchen in our basement guest suite, which is an ideal home laboratory. Not everyone is lucky enough to have a room or even a corner that can be dedicated to a laboratory. Fortunately, there are many alternatives.
Kitchen
Let's get this one out of the way first. The kitchen may seem to be an ideal location for a part-time laboratory. There's usually plenty of counter space and storage, hot and cold running water, good lighting, plenty of electrical outlets, resilient flooring, and the exhaust fan over the stove can serve as a field-expedient fume hood. In fact, unless you limit yourself to using only nonhazardous chemicals, the kitchen is about the worst possible choice for a part-time lab. Food and laboratory chemicals are a dangerous combination. Still, thousands of home labs over the years have been set up in kitchens, and the kitchen may be your only option. If so, take extreme care to prevent any contamination from occurring. Protect the counter or table surface (and, if possible, the floor) with a resilient chemical-resistant mat, and clean up thoroughly after each lab session. Make sure that all of your equipment and particularly your chemicals are returned to their storage containers and that none are missing.
Laundry room
Many laundry rooms are ideal candidates for a part-time lab. Laundry rooms are usually well-equipped with electric power, water, drain, lighting, and have adequate ventilation. There is often sufficient storage and if not it's usually easy to add more. There is probably a suitable work surface available, and if not it's usually easy to add a fold-down or other temporary work surface. The floor of most laundry rooms is concrete or vinyl, which minimizes the danger of damaging it with spills. In most homes, the laundry room is the best choice for a part-time lab. Of course, you have to clean up carefully after each lab session to avoid the risk of staining or damaging clothes.
Spare bathroom
A spare bathroom is often an excellent location for a part-time laboratory. It provides running water and a drain, plenty of electric receptacles (with ground-fault circuit interrupters), good lighting, and good ventilation. Many spare bathrooms are a bit short on storage and counter space, but that's often easy to remedy simply by constructing a collapsible framework that supports a plywood work surface over the tub. Particularly if you live in an apartment, a spare bathroom may be the best choice for a part-time lab.
Basement workshop
A basement workshop area is generally not an ideal location for a part-time lab, but may be the only option. On the plus side, storage and work surfaces are usually not a problem, the floor is often of concrete or another relatively impervious substance, and electric power is usually available. However, ventilation is often inadequate, and many basements have no water supply or drain.
Garage or garden/storage shed
For some people, the garage or garden/storage shed will be the location of last resort. There are some good points to using such a location as a part-time lab (or even a full-time one). Storage and work surfaces are usually plentiful or can easily be made so, ventilation is often adequate, there is usually electric power available, and spills that damage the floor or work surfaces are of less concern than they would be in a finished area of the house. Weighed against this, it may be a long trek to the nearest sink and drain (although you may be able to use the garden hose as a water supply). Perhaps the worst aspect of using such a location is the lack of climate control. You'll swelter in the summer and freeze in the winter. Even if you can tolerate that, it's not the best environment for storing your equipment and supplies or for doing controlled experiments.
Temperature Matters
If your work area is not heated and air conditioned, give some serious thought to chemical storage. The shelf life specified for many chemicals assumes storage at normal room temperature. Allowing a chemical to bake in the summer heat of a storage shed or garage may reduce that shelf life from a year or more to a few weeks or even days. Less obviously, storing some chemicals at low temperatures may be a bad idea. Glacial acetic acid, for example, freezes at 16.7°C (62.1°F), and the solutes in solutions that are nearly saturated at room temperature will crystallize out at low temperatures. More importantly, some chemicals that are reasonably stable at room temperature may decompose or become unstable if they are stored at high temperature.
Finally, I thought you might like to see some images of our home lab, where we do chemistry, biology, earth science, forensics, and physics work. If it looks like a kitchen, that's because it used to be the kitchen in our guest suite. Now that the kitchen has been permanently converted to lab space, overnight guests just have to use the main kitchen. Oh, well.

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