The many benefits of environmentally safe detergent outweigh the downsides of the plastic packaging. However, the ideal scenaraio would be to buy that eco-safe detergent in powder form—especially if your option for liquid comes in an unrecycled plastic container.

What’s so bad about detergent? Well, each year, billions of pounds of laundry-detergent chemicals—released in wastewater drained down sinks and from washing machines—find their way into waterways, where they threaten aquatic life. Among these chemicals are petroleum-derived surfactants (the stuff that cleans), builders (which boost the cleaning action), and optical brighteners (chemicals that convert UV light wavelengths to visible light, thus tricking your eye into seeing the laundered clothes as "whiter."

Although sometimes advertised as "biodegradable," many of these ingredients actually biodegrade into byproducts that are more toxic than their parent compounds. The artificial fragrances contained in most conventional laundry detergents are also petroleum-derived. Synthetic perfumes, which can irritate sensitive skin, also contain phthalates—a group of chemicals that have been linked to reproductive disorders, hormone disruption, and cancers in laboratory animals.

Environmentally responsible detergents are made without the use of phthalates or harsh chemicals. They replace petroleum-based cleaning agents with non-polluting plant-based cleansing agents that break down into non-toxic elements. These detergents are typically fragrance-free or might use non-synthetic botanical scents.

Other than packaging and water content, the main difference between liquid and powder detergents is the use of sodium compounds as "fillers" in powdered detergents. Although sodium salts can drain into oceans and lakes with minimal effect, they can harm plants and animals if graywater (the water that goes down your sink drain) or wastewater treatment effluent (the stuff that is left after raw sewage is treated) is used for irrigation. These salts also raise the acidity of the water, which can irritate sensitive skin.

Packaging for both liquid and powder detergents can be made with recycled content, and both types of packages are highly recyclable. You can also reduce the amount of packaging you consume by purchasing ultra-concentrated varieties, and by using less detergent per load. Just be sure to follow measurement recommendations.

And in case you were curious, the energy savings realized by replacing the petroleum-based ingredients with plant-based ingredients is effectively nullified unless you buy the non-toxic liquid detergent in a recycled-content plastic container.—Colleen Howell