Definitive answers to the most common household battles over sustainability. A house divided cannot stand. Yet making eco-friendly choices at home can be divisive.

Couples squabble over whether green cleaning products really work. Is it more efficient to roll down the car windows or turn on the air conditioning? The proper way to load a dishwasher can spark endless debates. It’s time to lay a few of these debates to rest.

I set out to answer common threats to domestic tranquillity with hard data. It might be the evidence you’ve been seeking to settle an argument or, be warned, the ammunition your spouse needs to say: “I told you so.” Do green cleaning products work as well as conventional products? Many dismiss eco-friendly cleaning products as ineffective, and for many years that was an accurate assessment, says Jason Marshall, who runs the laboratory of the Toxics Use Reduction Institute (Turi) at the University of Massachusetts at Lowell.

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