The word 'concentrated', as expressed here, merely means "the state of being less dilute". A product can be non-toxic and 'earth-friendly' and still be concentrated just as it can be full of lethal chemicals but not be in the least bit concentrated. Toxicity levels of a product are in no way connected to the amount of water or other solvent they contain. By the way, it is high time that someone properly defined the oft-used term 'earth-friendly.' Who can presume that he or she has the unique ability to be able to determine what products or substances may or may not be 'friendly' to the earth?