VOC for German Paints

Q. Just looking at VOC content limits in paint. The German Blue Angel Low-Emission Wall Paints standard, RAL-UZ 102 (5/00) specifies a VOC content of 700 parts per million. What is the equivalent in grams per liter? Just wanted to check my calculation.

A.Thanks for a really great question. Unfortunately, I do not know the German environmental regulations and so don't know how they present their units. Based on my lack of knowledge on this issue the following questions arise:

In the US our units for VOC are in grams (weight) per liter (volume), such as 420 g/L. Therefore, by quoting 700 parts per million I don't know if the "700" is by weight and the "per million" is by volume, or if all the units are by weight or all the units are by volume.

Also, I assume that if the coating is a wall paint then in all probability it contains water. Is this so? In that case we would need to know the water content to calculate the VOC in g/L, LESS WATER! Knowing the VOC content INCLUDING water doesn't help you with a prohibitive rule compliance analysis, but the information is helpful to calculate compliance with permit conditions.

For your information, I'm sponsoring a four-day environmental/paint training program on this very topic in January in California. During the class I teach participants how to perform up to 20 different types of calculations to determine compliance and also to deal with permitting issues. If you want to know more about the class, please go here.