Important Features: Light bulbs

Important Features: Light bulbs

Full-spectrum lighting is controversial

It's easy to assume that full-spectrum lighting -- or any light close to it -- is "more natural" and therefore better than warm light that's more yellow and red. However, lighting experts say that warm colors (reds, oranges, yellows) look better under the warm light cast by 2700K to 3100K light bulbs. Also, quite a few owner-written reviews say warm or "soft" light is more relaxing and pleasant than cooler light.

Cool colors -- blues and greens -- do look better under cooler lighting, and higher-K light bulbs do make it easier to judge colors. Experts say that true full-spectrum lighting is a must for displaying artwork or judging colors for photography, digital art prints, etc. Some studies (and owners) say 5000K lighting is ideal for task lighting or other situations where it's important to stay alert.

Despite various manufacturers' and retailers' claims that full-spectrum lighting offers health and performance benefits, studies are mixed. Health Canada analyzed studies and found that the evidence doesn't justify such claims. However, more recent studies are accumulating evidence that the blue part of the spectrum does raise alertness and help people wake up in the morning. Blue LED light has even been used to treat seasonal affective disorder (SAD) or under medical supervision, to correct sleep-wake cycle problems. But it also poses some health risks -- making warmer light bulbs a better bet unless you know for sure what you're doing.

Ophthalmologists are raising concerns that the blue part of the light spectrum increases the risk of macular degeneration -- a major cause of blindness. This is especially relevant for an aging population. New lenses implanted in cataract surgery are designed to filter out blue light in order to protect against macular degeneration, and quite a few sunglasses and goggles filter it out for the same reason. So experts warn that it's not necessarily a good idea to use full-spectrum light bulbs for general lighting.

Blue light also may be associated with a higher risk of certain cancers, including breast cancer. Some studies show that exposure to blue light at night decreases melatonin production, which is important in preventing cancer cells from dividing. Red and yellow light, on the other hand, has minimal effect on melatonin cycles.

Light bulbs and other health concerns

"Full-spectrum" lighting isn't the only health concern that various experts have raised about light bulbs. Other concerns include electromagnetic fields (EMF) and the possible release of toxic chemicals, including mercury, if a compact fluorescent light bulb gets broken. We found some studies of both risks. UV light is of less concern, since reviews say that light bulbs emit relatively little UV light in comparison with sunshine. Nor do current ENERGY STAR compact fluorescent light bulbs flicker at rates apt to pose a health risk.

Although there's evidence that exposure to electromagnetic fields is hazardous for children -- with a connection to leukemia rates -- it's not clear whether or not EMF poses a problem for adults. Apparently some people are more sensitive to such fields than others; if you've ever gotten a headache from one or more light fixtures or bulbs, you're apt to be one of them. Incandescent light bulbs don't emit a high electromagnetic field, but some compact fluorescent light bulbs do -- certainly the ones that use an iron-core electromagnetic ballast. If EMF is a concern, select a bulb with a solid-state electronic ballast.

In addition to mercury, fluorescent light bulbs also contain other toxic materials; most contain cadmium, lead, hexavalent chromium (as in the film "Erin Brokovich") and polybrominated biphenyls (one of the latest health scares in the news). Hence, reviews say it's a good idea to familiarize yourself with the safest cleanup procedure when buying compact fluorescents (or any fluorescent light bulb, for that matter). See Best Research for some helpful links.

Of course, disposing of unbroken defective or used fluorescent light bulbs is a major environmental concern. A few localities have ample recycling facilities in place, but proper disposal of hazardous light bulbs is still a real problem in many areas. Online resources can help; see the Best Research section below.

• Match the light bulb type and power to the situation. Ideally, reserve fluorescent lights for settings where you need light for hours at a time. For three-way lamps, dimmers or damp areas, be sure you're buying a light bulb that's labeled for that purpose. Some compact fluorescent light bulbs work best when mounted base-up, others base-down -- and may vary in brightness and longevity depending on how they're mounted.

• Lifetime ratings are only the median number of hours a bulb lasts. In other words, half the light bulbs of that model will burn out later, half earlier. So don't take the "rated for X hours" as anything more definite than that.

• Be sure the light bulb turns on fast enough to serve your needs. Experts recommend using LED, halogen or incandescent light bulbs for stairways or halls where you need instant light for safety.

• For compact fluorescent lamps, look for recent ENERGY STAR certification. Even recently tested ENERGY STAR-certified lamps can vary in reliability and quality, but expert reviews advise avoiding dollar-store and other very cheap light bulbs entirely.

• Choose a Kelvin color temperature that suits your taste and purpose. Ordinary incandescent light bulbs and warm or soft white fluorescents are usually 2700K (yellowish), showing warm colors to advantage and providing a more relaxing light. At the other extreme, "daylight" fluorescents are 5000K, bluish-white like the sun at noon.

• Compare light output by lumens. When comparing different types of light bulb, use the lumen ratings to compare output -- but remember that compact fluorescent light bulbs take several seconds to attain full brightness. Over their lifetime, they gradually get dimmer. Reviews recommend choosing a compact fluorescent that's a little brighter than the incandescent light bulbs you usually use.

• Match brightness to color temperature. Oddly enough, experts say that whiter, higher-Kelvin light bulbs are usually perceived as too dim unless you increase the brightness. So "daylight" bulbs (whether incandescent or fluorescent) need to be brighter than warmer-temperature light bulbs.

• Compact fluorescent lamps are most pleasing when the CRI is 80 or higher. The color rendering index (CRI) compares the light bulb's color to that of an ordinary incandescent light bulb (which has a CRI in the 90s). Fluorescent light bulbs range from 50 to 99, with low-CRI bulbs making skin look unhealthy and colors look odd.

• Keep heat in mind. The higher the wattage of a compact fluorescent light bulb, the hotter it burns. Reviews say air flow is important to keep the heat from shortening the bulb's life; the ballast is in the base, so using a fixture that keeps the base below the spiral or globe can make the bulb last longer.

Light bulb recalls

For light bulbs that screw into a medium-base socket, the only safety recalls we found are for compact fluorescent bulbs -- and only as recently as 2004. (The dimming ballasts recalled in August 2006 were used only in light bulbs with a four-pin base.) In October 2004, the Consumer Product Safety Commission (CPSC) and Technical Consumer Products recalled 32-watt 3-way compact fluorescent light bulbs sold under the Commercial Electric and DuraBright brands. The bulbs were sold nationwide at The Home Depot and Orchard Supply Hardware from April 2004 through November 2004; for more information call Technical Consumer Products at 800-397-2647.

Two other recalls occurred in October 2004. Globe Electric recalled 13-watt spiral compact fluorescent light bulbs shipped from China to the United States in 2003. Also, Teng Fei Trading Company recalled several compact fluorescent light bulbs sold at dollar stores in the state of New York because electrical components could overheat and cause a fire. (We read quite a few reviews advising against buying compact fluorescent light bulbs in dollar stores, or at that low a price anywhere.)

Light bulbs, unlike power tools and appliances, aren't normally registered with the manufacturer even when they carry long warranties. So experts say it's a good idea to check the CPSC website periodically.

Our Consensus Report shows how many times products are top-ranked by reviewers included in our
All The Reviews Reviewed chart.

Among basic compact fluorescent light bulbs, Philips Marathon and N:Vision Soft White share top ranking in reviews, but N:Vision offers better warranty fulfillment. The Fresh2 light bulbs not only save energy, but eliminate odors. We found fewer reviews of LED light bulbs, but both C. Crane and EarthLED light bulbs get good marks for certain situations. "Full-spectrum" incandescent light bulbs also get some good reviews, including GE Reveal, Sylvania Daylight and Verilux.