Have you heard about the ingredient in shampoos and bath washes called Sodium Lauryl Sulfate or Sodium Laureth Sulfate?
—Carol Bean, Lyme, NH
Sodium Lauryl Sulfate (SLS) is a cleanser derived from coconut oil, used in a variety of household and industrial products. Sodium Laureth Sulfate (SLES) has similar foaming and cleansing effects, as do both chemicals’ ammonia-based cousins. Anti-SLS/SLES propaganda pervades the Internet and alternative product packaging, but rarely coincides with scientific research.
The Cosmetic, Toiletry and Fragrance Association’s Food and Drug Administration-approved experts panel, the Cosmetic Ingredient Review (CIR), has deemed SLS and Ammonium Lauryl Sulfate “safe in formulations designed for discontinuous, brief use followed by thorough rinsing from the surface of the skin.” The CIR has likewise declared SLES and Ammonium Laureth Sulfate safe in cosmetic formulations.
In higher concentrations, SLS and SLES can cause dermatitis and eye irritation, but no research has suggested any link to other medical disorders. Critics of SLS frequently mention, without citation, a study from the Medical College of Georgia (MCG) purported to show that SLS inhibits children’s eye development, causes cataracts, builds up in critical organs and could lead to baldness. However, according to MCG Regents Professor of Ophthalmology Keith Green, the report’s author, “My work does not lead one to that conclusion in any way, shape or form.” The actual paper claims only that diluted SLS solution inhibits repair of lesions in a specific corneal membrane—there’s not one word about baldness.
Still, SLS has been shown to facilitate dermal absorption of three chemicals (carbaryl, benzedine and parathion) and likely others not tested. The real worry about SLS lies in its power over other chemicals in SLS-based products. Some shampoo components can be contaminated by carcinogens during production—SLES can bear traces of Dioxane, while alkyloamides such as Cocamide DEA can be contaminated with nitrosamines. A rigorous background check of shampoo’s supporting players is definitely in order.
Which is better for emissions, synthetic oil or conventional?
—David Bedell, New Canaan, CT
Conventional oil is derived from petroleum refining; synthetic oils are chemically manufactured replicas. Conventional oils contain impurities that build up, forming deposits in the car. Synthetic oils, by contrast, keep the engine clean and generally free of debris, and can stay on the job three times as long. But synthetics are also more than three times more expensive. Whether it’s worth the expense is a subject of frequent, inconclusive debate among enthusiasts. Notably, one Corvette’s warranty is voided if conventional oil is ever used.
Nearly all of an automobile’s emissions are caused by the combustion process (the burning of gasoline to make energy). When your car’s engine is badly worn or out of tune, the tailpipe emissions of such noxious byproducts as carbon monoxide, hydrocarbons and particulate matter are greatly increased. Motor oil facilitates the combustion process, but is not involved in the chemistry, and thus its content is not a significant factor in emissions.
Oil is a cause of some emissions when your car is burning oil, of course. Synthetic oils and conventional oils release basically the same pollutants when burned, so there’s no advantage in using one or the other. If your car is burning oil, you shouldn’t just change the oil to something less polluting; you should take it to a mechanic and get it fixed as soon as possible. There is, unfortunately, no quick route to “greening” an internal-combustion car.
Does the environmental movement hurt the economy?
—Dustin Calvo, Grants Pass, OR
Although corporations often use slanted think tanks to manipulate public opinion on this issue, the question remains: are they right?
Most economists say no. The classic assumption is that environmental regulations raise prices, force downsizing and cause companies to relocate operations to environmentally careless countries overseas. However, U.S. Census Bureau data found that the total 1991 pollution control expenditures—shortly after renewal of the Clean Air and Clean Water Acts—were a fairly insignificant part of raised prices and corporate profit loss. According to the Environmental Protection Agency, the increase would rarely be enough to force plant closings or layoffs. The overseas “pollution haven” hypothesis, meanwhile, is almost entirely unsubstantiated, with 30 years of general rule over a handful of hyped exceptions.
Department of Labor statistics show that workers are 500 times more likely to be laid off by factors other than environmental regulations. A few well-publicized examples, such as the loggers hurt by spotted owl protection in the Pacific Northwest, support the idea of regulations’ negative economic impact on the job market. In The Trade-Off Myth? (1999), economist Eban Goodstein notes that environmental regulation often increase? the number of available jobs, although the nature of the jobs shifts. This won’t help loggers much, but the economy will remain prosperous.
Widespread employment insecurity pops up whenever environmental regulations are a political issue. Don’t believe the hype!