Clearing The Air: Understanding VOCs

Thanks to stricter regulations and increasing consumer demand for products that are healthier and more sustainably produced than their conventional counterparts, environmentally friendly paint has become the fastest growing segment of the $21 billion paint and coatings industry.  Nearly every major manufacturer has a low or zero VOC product now, and many startups have introduced brands that claim to be not only safer but more durable and better performing than the generation of eco-friendly paints that preceded them to market in the 1990's.

Volatile Organic Compounds

Volatile organic compounds (VOCs) are a class of carbon-based chemical solvents that have historically been used as ingredients in paint for the purpose of spreading evenly and adhering to surfaces.  They are what we associate with the odor of new paint.  At room temperature they evaporate rapidly (often referred to as off gassing), and once airborne, they combine with other molecules to create compounds, some benign, some much less so.  We've all experienced the after effects of VOCs in the form of headaches, nausea and eye irritation, but prolonged exposure can lead to more serious health problems, such as organ damage and respiratory disease.

Rocky Mountain Park on a clear day and a smog day   

VOCs and Greenhouse Gases

Until now the federal government has capped the VOC content in paints at 250 g/L for flat finishes and 380 g/L for other finishes, but this has proved insufficient in managing the increasingly damaging effects of air pollution on human health and habitats.  According to an EPA study, the VOCs in paint products alone account for 9% of the pollutants that cause greenhouse gases and smog, which contribute directly to global warming.

Many regional authorities have mandated stricter limits; in California, for instance, the South Coast Air Quality Management District has the toughest standards: in addition to dropping the allowable VOC content of house paints sold in the three county region it manages to 50 g/L, it plans to impose an emissions fee for manufacturers whose products exceed this specification.  The EPA, meanwhile, has announced it will propose cutting its limits by more than half for most finishes.

VOCs Don't Tell The Whole Story

This single-minded focus on VOCs, however, is not the whole story when it comes to evaluating the environmental friendliness of paint products.  It is still possible to have a low or zero VOC paint that contains known carcinogens, mutagens and other toxins, as evidenced by the hazardous materials warning on can labels.  And, too often the pigments that are used to tint paint increase the VOC content of the finished product significantly, something that consumers are largely unaware of.

Fortunately, credible organizations such as Scientific Certification Systems and Green Seal have developed standards for testing the environmental and health benefits of these products, so that design-build professionals and consumers alike can buy them with knowledge of their complete environmental profile.

The FAQs on VOCs

Q:  What's the difference between low and zero VOC paints?                       

A:  Low VOC paints contain less than 50 g/L of VOCs; zero VOC paints contain 5 g/L or less of VOCs.

Q:  Do these paints perform as well as other higher VOC paints?                

A:  Yes, they perform as well, if not better than, other higher VOC paints.  As with any product, there will be variation in performance from one brand to the next.  Many startups have introduced products that outperform their conventional counterparts in coverage, hide and wear and have superior environmental profiles, as well.

Q: Are all low and zero VOC paints non-toxic?                                            

A:  No, most zero VOC paints still contain formaldehyde, ethylene glycol, crystalline silica and other solvents and substances that are known carcinogens, mutagens and reproductive toxins.  Check can labels for hazardous materials warnings.

Q:  Can these paints seal in off gassing?                                                   

A:  Most of these paints are formulated to minimize off gassing, but still breathe, to allow for a healthy exchange with outdoor air.  Sealing the wall surface would trap harmful chemicals that off gas from other products and finishes on the walls.

Q:  How long do paints off gas?                                                                    

A:  This is widely debated and there is no consensus on the subject.  At one end of the spectrum there are those that say off gassing is over when the odor has dissipated; and, at the opposite extreme, that it can go on for upwards of 10 years.  How long paints emit is really a function of many variables, such as the type of paint (oil- or water- based, flat or other finishes, the VOC content), the surface being painted (drywall, wood or metal), the climate (humid or dry) and ventilation.                            

The EPA did a study in 2002 which is a good touchstone.  They found that conventional latex paint applied to metal off gassed 90% of its VOCs within two weeks, but the same paint applied to drywall off gassed less than 20% in the first two weeks and continued to off gas for up to 42 months.  It's important to consider the off gassing of all the products and finishes in an enclosed area, and not just the paint, when reducing VOCs and toxicity to improve indoor air quality.

Q:  Do these paints cost more?                                                                  

A:  No, in most instances these paints cost about the same as other premium paints, with the considerable advantage of also being environmentally friendly.  Of course, some manufacturers have passed the cost of their R&D on to consumers in the form of higher prices, anticipating lower prices as sales increase.

Q:  Do these paints last as long?                                                                   

A:  Yes, the better brands have been formulated for superior performance and should last as long, if not longer, than their conventional counterparts.  Within the product category, however, we have seen considerable variation in scrub tests, so its best to consult some of the excellent third party certification programs for more information.

Q:  What colors do these paints come in?                                                      

A:  There are no limits to the colors these paints come in--they can be tinted in everything from subtlest pastels to the boldest accent colors, in Flat and Eggshell finishes.  

Q:  Do these paints require special colorants?                                              

A:  Zero VOC colorants are available, but not widely in use.  Ask your dealer what type of colorant they use (low or zero VOC) to determine if the colorant will increase the VOC level of the finished product.

© Casa Verde Paint 2011