Week of 12/3/2006

Dear EarthTalk: I"m concerned about all the talk of using hydrogen for fuel. Isn"t hydrogen what caused the Hindenburg blimp to explode back in the 1930s?

—Doug, via e-mail

The explosion of the Hindenburg blimp in Lakehurst, New Jersey in 1937 killed 36 people and was one of the worst air disasters of the period, but hydrogen was probably not the culprit. Addison Bain, a National Aeronautics and Space Administration (NASA) researcher, investigated the Hindenburg crash in 1997. He concluded that, while the Hindenburg did use hydrogen for buoyancy, the cause of the accident was an electrostatic charge that ignited the blimp"s highly flammable waterproof skin, made from a mixture of lacquer and metal-based paints that Bain likened to rocket fuel.

Others argue that a spark ignited hydrogen that was leaking from the ship. But witnesses described the fire as very colorful, whereas hydrogen burns without much of a visible flame. But whether or not hydrogen caused or simply contributed to the ensuing blaze, hydrogen is indeed flammable, and can burst into flames when it comes into contact with fire or another ignition source.

But gasoline, by far the most common automotive fuel in the world, is much more flammable than hydrogen. According to hydrogen proponent Daniel Emmett of Energy Independence Now, hydrogen is 14 times lighter than air and when it catches fire it disperses and extinguishes quickly. Gasoline, on the other hand, is heavier than air and stays flammable much longer. Many people don"t realize, Emmet adds, that hydrogen has been used safely for decades in many industrial and aerospace applications.

Besides being less flammable than gasoline, hydrogen has many other benefits. It is nontoxic, which is more than can be said for any petroleum-based fuel. Furthermore, the processing (not combustion) of hydrogen in fuel cells produces no harmful pollutants and emits only pure, potable water as well as heat that can be recaptured for other uses. In contrast, the combustion of gasoline and other automotive fuels leads to acid rain, smog and global warming, among other environmental problems.

Despite its benefits, the widespread adoption of hydrogen as an automotive fuel is not yet close at hand. Techniques for producing, storing and transporting hydrogen have to be standardized, and costs reduced substantially. Some hydrogen proponents see a future where hydrogen will fuel vehicles at service stations, as is now done with gasoline; others see a future in which people fuel their cars at home from appliances that make hydrogen from electricity or, further down the road, from solar energy.

In 2003 the Bush administration committed $1.2 billion to a hydrogen initiative in order to "reverse America’s growing dependence on foreign oil by accelerating the commercialization of hydrogen-powered fuel cells to power cars, trucks, homes and businesses with no pollution or greenhouse gases." Under the initiative, says the White House"s "Hydrogen Economy Fact Sheet," "the first car driven by a child born today could be powered by fuel cells."

CONTACTS: "Hydrogen Exonerated in Hindenburg Disaster," National Hydrogen Association News; Energy Independence Now; White House "Hydrogen Economy Fact Sheet"

Dear EarthTalk: I"m a hair stylist and am wondering about the health and environmental impacts of the styling products I use every day on my customers.

—Misty Rohrbaugh, Asheville, NC

Millions of people around the world use shampoos, conditioners and dyes on their hair regularly without any discernable harm. But recent studies have linked some of the ingredients in these products to various human health problems, so hair care professionals and consumers are well advised to know their options.

Traditional shampoos and conditioners, the most commonly used hair care products, contain a synthetic detergent called Sodium Lauryl Sulfate (SLS), which generates a sudsy lather. But SLS can dry the scalp, stripping the skin"s surface of its protective lipids. It can also cause follicle damage, hair loss, skin and eye irritation, and allergic reactions such as rashes and hives.

Other problematic chemicals in most mainstream shampoos and conditioners are parabens—sometimes listed as methylparaben, propylparaben, ethylparaben or butylparaben—which are added as preservatives to ward off mold and mildew. Morris Shriftman, Senior Vice President with Avalon Organics, says that these chemicals are dangerous because they accumulate in the bloodstream where they can "mimic" naturally-occurring hormones like estrogen, and disrupt human endocrine function accordingly. Parabens are also of particular concern to oncologists, who report finding the chemicals in breast cancer cells.

Luckily, a number of manufacturers make available shampoos and conditioners free of SLS and parabens, making it easier for stylists and customers alike to do the right thing. Aveda, Avalon Organics, Aubrey Organics, Dessert Essence Organics, Jason Natural Products and Simply Organic, among many others, use organic herbal extracts to do the jobs normally associated with synthetic chemicals. These products are readily available at natural foods markets and increasingly in mainstream supermarkets.

Studies trying to prove links between hair dyes and cancer or birth defects have turned up mostly inconclusive results, although the U.S. Food and Drug Administration"s (FDA"s) National Center for Toxicological Research found that the majority of off-the-shelf hair dyes for black, red and blonde hair contain a known carcinogen, 4-ABP. Also, according to the FDA, some consumers have reported burning, redness, itching and swelling of the face from hair dyes, as well as hair loss and difficulty breathing. The FDA does not regulate hair products, but John Bailey, director of the agency"s color and cosmetics program, cautions consumers to "consider the lack of demonstrated safety" when considering a hair dye.

Most natural health care experts agree that going without hair dye altogether is the safest route. Hair color professionals should wear heavy plastic gloves and a mask to protect against fumes, and should schedule their color work with lots of breaks between applications to limit exposure. Consumers, when possible, should shop around for less toxic, all-natural coloring agents. Many of the companies listed above also make all-natural hair colorings; other popular brands include EcoColors, Naturtint, and Clairol"s Castings line. Hennas, which are available in most salons, are also a good safe, non-permanent option.

CONTACTS: , FDA Office of Cosmetics and Colors