This can be a difficult question to answer, especially given the amount of greenwashing around today.  One way to get some assurance a product is what it claims to be is to check for well-respected, third-party green-certification.  Here are some organizations that can provide assistance:

Energy Star: Energy-efficient guidelines are set by U.S. Department of Energy for appliances, heating and cooling systems, lighting, roof products, windows and doors. www.EnergyStar.gov

FSC: Forest Stewardship council that sets standards for responsible forest management and certifies materials from specific woodlands. www.FSC.org

Green Seal: Maintains environmental standards for many products, including adhesives, paints, windows, cleaners, papers and alternative-fuel vehicles. www.GreenSeal.org

LEED: Leadership in Energy and Environmental Design. The U.S. Building Council rates buildings in categories such as water conservation, energy-efficiency, materials used and indoor air quality. Products themselves do not earn LEED points – only a complete project can be certified. Some materials can help a building qualify for certification. www.USGBC.org

SCS: Scientific Certification Systems certifies environmentally preferable products and services. Among them, carpet, cabinetry, paint, doors and flooring. www.SCScertified.com

Cradle to Cradle (C2C): Sets rigorous standards for “environmentally intelligent” design by examining the entire lifecycle of eco-friendly materials. www.C2CCertified.com

In addition to identifying false or exaggerated claims, factors such as the distance and manner in which a material is transported need to be considered. Not to single any particular material out for inspection, but an example is “sustainable” bamboo flooring.  Sustainable rocks, but for those of us living in the U.S., this material traveled a great distance. Bamboo flooring is frequently used in LEED certified projects, but having been shipped so far - it really “green”? That would depend on whom you ask. (This is a tough one for me – I love bamboo flooring.)

Other questions to ponder are:

Is the material produced in an environmentally responsible manner? Example:  IceStone makes use of day lighting in their facility and recycles gray water.

Does the product contain a percentage of recycled materials? Example: Vetrazzo uses 100% recycled glass and EcoTop is composed of a FSC certified fiber that is a 50/50 blend of sustainable bamboo and post consumer recycled paper.

Can the material be recycled at end of its lifespan? Example: Earthweave, Flor and Vetrazzo offer programs that take back used product from customers and recycle it.

With all of this to consider it seems to me that “green” is on a continuum, just like the rest of life. No material is perfect and there is, perhaps, a lot of gray (area) in green. However, as our collective eco-conscious continues to grow, environmentally responsible decisions are bound to follow.