Wal-Mart is continuing its march toward sustainability by offering the latest eco-friendly asthma inhaler at a fraction of the price of competing products.

The FDA outlawed the use of ozone-damaging CFCs (chlorofluorocarbons) in inhalers beginning in 2009, so many manufacturers are switching to the less injurious HFA (hydrofluoroalkane) instead. While HFA inhalers are generally comparable in performance to those that include CFCs, they also tend to be somewhat more expensive, with prices between $30 and $60. This can be a problem for people on limited and fixed incomes—and as it happens, asthma tends to occur more frequently in that very group.

This is where Wal-Mart comes in. The ReliOn(R) Ventolin HFA inhaler, which will be sold exclusively by the retail giant, is priced at $9.95, bringing it within reach of many suffering asmathics.

Sustainability isn't just about the environment; it's also about social equity. This is the sustainability issue Walmart is addressing with its affordable inhaler.

There's an important reminder in this. For years, Wal-Mart has been getting lambasted for everything from its employment practices (which can help to keep their prices down)  to its impact on local culture and communities. Putting the merit of these critiques aside for the moment, they've mainly been the province of people with middle-class or better lifestyles—and what these critics have tended to overlook, for the most part, is the fact that with its cheap prices, Walmart has offered a better quality of life to consumers in the lower income range.

In this admittedly limited sense, Wal-Mart was supporting social equity long before the word "sustainability" ever entered its lexicon. Now the challenge for the company is to expand its practices so that they're more uniformly supportive of social equity and environmental health. The company low-cost HFA inhaler represents another stepping stone for the company in its pursuit of this strategy.