Form-release agents or form oils represent only a small fraction of the cost of a manufactured concrete item, but they have a big influence on the quality and appearance of the concrete surface.

Today, precasters can choose from among hundreds of form-release products, and new ones are still being developed. Many changes have been introduced as manufacturers scramble to meet federal and state environmental regulations, particularly with respect to volatile organic compounds (VOCs).

Release agents are classified by how they work rather than what they contain. Two basic categories are barrier agents and chemically active agents (also referred to as reactive agents). Some release agents are a combination of the two types.

VOC emissions from architectural coatings under Section 183(e) of the Clean Air Act were enforced throughout the United States beginning Sept. 13, 1999. Form-release agents, which are classified by the act as architectural coatings, are among the products affected.

Although the regulations apply directly only to manufacturers, they will set limits on what producers can buy as a release agent.

A six-page form-release agent selection guide, compiled from manufacturer information, answers some of your questions.