Laundry detergents have come under the microscope, but it’s not easy to know what to look for when everyone just wants something that will smell nice and get the laundry done.

It’s important to know why some chemical additives are so nasty, though.

In the 1960s, detergent advertisements touted how long their suds lasted compared to competitor brands. But there was an unintentional side effect of these durable detergents: soapy bubbles began appearing in Niagara Falls. Companies were forced to reformulate.

Today the biggest concern is phosphates, which are added to soften the water and make the detergent more effective. Once waste water exits your washing machine, it ends up in lakes, rivers, and other waterways. Phosphates encourage the growth of algae, which can choke an ecosystem and kill fish and wildlife.

When algae forms, it rises to the surface to form scum. Eventually the algae plants die and sink to the bottom, where they decompose and use up oxygen in the water. Without sufficient oxygen, nearby fish and plants suffocate.

Phosphate pollution has become such a problem in Canada that the federal government passed a law to limit the chemical’s use in laundry detergents by 2010.

Chlorine bleach is another common additive to laundry detergents that can impact not only the water supply, but the air you breathe as well. It releases fumes that contaminate the air in your home, particularly if it is not well ventilated. The tainted air can irritate eyes, skin, and lungs, and once washed down the drain it reacts with other chemicals to create pollutants like the carcinogen dioxin.

However, there are options to help reduce the environmental impact of the necessity of washing those gym shorts.

Oxygen bleach is a great alternative to chlorine bleach because it is nontoxic and breaks down into oxygen and salt. It’s packaged under many names – Oxiclean, Biokleen, and Ajax among them – but is an effective bleaching agent that’s perfectly safe on colors, carpets, and upholstery as well.

Powdered detergent in general is environmentally preferable to liquid. Powders require less packaging and energy to ship than heavier liquids. Additionally, liquid detergents are approximately 80 percent water – a waste when you consider how much water is used by your washing machine in a typical cycle. Concentrated liquid detergents are also a good choice, and they’re becoming increasingly available as more households upgrade to high-efficiency washers and dryers.

Ecological laundry detergents, such as those by Mrs. Meyers Clean Day and Seventh Generation, have also started appearing on the shelves in Target and Whole Foods. They boast cleaning agents derived from plants, borax, and grime-fighting enzymes, and they’re scented with lavender, eucalyptus, lemon verbena, and other herbal fragrances.

So what’s the difference between an ecological laundry detergent and Tide? According to Seventh Generation’s website, neither detergent contains those highly polluting phosphates. However, Seventh Generation doesn’t make use of bleaching agents or optical brighteners in its formulation, and uses bases like palm kernel oil instead of the petrochemicals that are typical in standard laundry detergents. Palm kernel oil is easily renewable whereas petroleum-based products are not, so Seventh Generation detergents biodegrade more easily.

The difference in cost is negligible. The average cost of a 32 ounce bottle of Tide is $5.13, compared to $5.80 for the same size container of Seventh Generation.
There is a trade-off, however. Seventh Generation’s own tests showed that its detergents performed at 85 to 90 percent the cleaning capacity of Tide. And Mrs. Meyers doesn’t offer a fragrance-free detergent, which could pose a problem for people with fragrance allergies or sensitive skin.

And speaking of skin, people who wash their clothes in cold water to save on energy use may be more prone to dermatological conditions. South Korean researchers found last year that hot water kills 100 percent of dust mites and bacteria commonly found in clothes, whereas warm water destroys only 6.5 percent. Hot water is also more effective at ridding laundry of pollen, pet dander, and other allergens.

Before you switch entirely to washing your clothes in cold water, consider first whether you have people with sensitive skin or allergies in your household. An environmental compromise might be to wash sheets, towels, and underwear in hot to kill bacteria, and do the rest of the load on cold.