What You Need to Know About VOCs

Literally, VOC means volatile organic compound, but when found on a product label it refers to a specific EPA definition found in the Code of Federal Regulations (40 CFR 51.100). Many common solvents that do not adversely affect ozone are excluded from the definition of VOCs, including:

• Acetone
• Tert-butyl acetate (some lacquers and solvents)
• Dimethyl carbonate (sometimes in MEK substitutes)
• Methylene chloride
• Most chlorinated solvents found in carb cleaners
• Less reactive, highly refined petroleum hydrocarbons, such as odorless mineral spirits
• Higher boiling hydrocarbons
• Solvents with boiling points greater than 250-degree Celsius (482 F).

Some VOC labels or EPA certification programs are based on the VOCs emitted from the product into the indoor environment and their possible related health impacts. However, some VOCs are regulated to control the formation of photochemical smog outdoors.

Therefore VOC labels and certification programs may not properly assess all of the VOCs emitted from the product, including some chemical compounds that may be relevant for indoor air quality. This is especially true of most wet products, such as paints or adhesives that may be labeled as “low-VOC” or “zero VOC.”

The bottom line is that a claim of “VOC-free” does not mean that there are no solvents, only that they are excluded from regulation due to either low evaporation or limited ozone reactivity. There is no human toxicity or safety component in the VOC rules.

Other critical factors include flammability and toxicity. Acetone, for example, is not a listed VOC and has very low toxicity in low doses. In fact, it is a natural metabolite that your body is quite used to removing.

However, because acetone evaporates very quickly, it is easy to get very high concentrations in the confines of a boat. The Occupational Safety Hazard Agency (OSHA) has assigned a permissible exposure limit (PEL) of 1000 ppm. It is also extremely flammable, a characteristic made more serious by its extremely rapid drying.

As a result, we use acetone very sparingly inside the cabin, preferring mechanical removal or a less volatile (slower drying) solvent that will put less in the air while I’m there. But acetone is a very practical and “green” choice for wiping down the hull due to its low air pollution impact, low toxicity, economy, and rapid drying. So long as we stay upwind and wear a mask, exposure is low and fire safety is a minor concern.

Bottom line: Regardless of the product label or marketing, read the product safety data sheet before using.

A product rated as low-VOC (volatile organic compound) does not necessarily mean it is safe to use without proper personal protection equipment.