What houseplants should I get to help reduce air pollution in our small apartment?

We value our homes as retreats from the pressures of the external world, but unfortunately the air we breathe there is not always as clean and pure as we'd like to believe. In fact, scientists estimate that indoor air pollution in modern houses may be several times greater than pollution outdoors.

Although plants can't cure major indoor pollution problems on their own, they are an ideal antidote to the minor contamination introduced into our environments through everyday household products and building materials. Plants produce oxygen, add precious moisture and remove toxins from the air through the tiny openings in their leaves. In fact, as few as 15 houseplants in an average-size home can offer a significant reduction in the number of indoor contaminants.

Look for plants such as philodendrons, spider plants (Chlorophytum comosum), and golden pothos (Epipremnum aureum) -- all have long been appreciated as houseplants for their decorative qualities and are highly effective in removing molecules of formaldehyde. This contaminant is present in many household items, including particleboard, carpet backings, some grocery bags, facial tissues, paper towels, and permanent-press clothing.

Flowering plants such as gerbera daisies and chrysanthemums are excellent choices for removing benzene -- frequently present in gasoline, inks, oils, paints, plastics, and rubber -- from the atmosphere.

Other hard - working and beautiful indoor plants include bamboo palm (Chamaedorea), Chinese evergreen (Aglaonema), English Ivy (Hedera helix), the indoor dracaenas (Dracaena "Janet Craig," D. marginata, D. massangeana and D. warnekii), mother-in-law's tongue (Sansevieria trifasciata laurentii), and peace lily (Spathiphyllum).

When choosing houseplants, remember that many (including some of those above) can be toxic if ingested, so be extra careful if you have young children or pets in your home. Staff at the local garden center should be able to advise you on nontoxic choices; contact your local poison-control center for guidance (the phone number is listed in the front of your telephone book).

I just bought a deep fryer. How should I store the used oil?

After using the oil, let it cool completely in the pan. Then place cheesecloth or paper towels in a sieve, and strain the oil into the original container if it's empty; if not, use a clean glass jar -- don't mix old and new oils.

Store the oil, tightly sealed, in the refrigerator. Oil that has been refrigerated often turns cloudy, but that's nothing to worry about.

You should only reuse the batch of oil to cook similar types of food. Discard oil after cooking with it four times -- sooner if it develops a rancid odor or smells like the foods you've cooked with it -- or if smoke appears on its surface before the temperature has reached 375 degrees ; when this is the case, it won't fry effectively.

Adapted from Martha Stewart Living Magazine. Questions should be addressed to Ask Martha, care of Letters Department, Martha Stewart Living,11 W. 42 d Street, New York, NY 10036. Questions may also be e-mailed to: mslletters@marthastewart.com. Please include your name, address, and daytime telephone number. Martha Stewart regrets that unpublished letters cannot be answered individually. For more on the topics covered in the Ask Martha column, visit marthastewart.com.