Ask the Expert Question-and-Answer Archive

by Ron Joseph

October, 2000

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.