Summary of the Use of Hexavalent Chromium

Specification and Use of Hexavalent Chromium.
Summary Report by Mark Lodge
The façade specifications on the Qatar Petroleum District Project allow for Chromium conversion treatment of aluminum sections as a surface preparation prior to painting.
The contractor has proposed hexavalent chromium to be used. The substance would be applied in the façade producers’ factory in the Peoples Republic of China.
Concern has been raised that hexavalent chromium represents a cancer risk and that it is actually banned in many parts of the world.
1. Overview of the substance:

Hexavalent chromium (also called chromium-6) is one form of the metallic element chromium, which is listed in the periodic table.
Characteristics of Chromium
Chromium is odorless and tasteless. It occurs naturally in various types of rock, soil, ore and volcanic dust as well as in plants, animals and humans.
Three Common Forms of Chromium
The most common forms of chromium in the environment are trivalent chromium (chromium-3), hexavalent chromium (chromium-6) and the metal form of chromium (chromium-0).
Chromium-3 occurs naturally in many vegetables, fruits, meats and grains, and in yeast. It is an essential nutritional element for humans and is often added to vitamins as a dietary supplement. Chromium-3 has relatively low toxicity.
Uses of Hexavalent Chromium
Hexavalent chromium and chromium-0 are generally produced by industrial processes. Chromium-0 is used primarily for making steel and other alloys. Hexavalent chromium is used for chrome plating and the production of stainless steel as well as leather tanning, wood preservation, textile dyes and pigments. Hexavalent chromium is also used in anti-corrosion and conversion coatings.
Potential Dangers of Hexavalent Chromium
Hexavalent chromium is a known human carcinogen when it is inhaled, and can pose a serious health risk to workers in industries where it is commonly used. Although the potential health risk of...