These volumes are arranged according to the complexity of the organic compound. In Volume 4, the chapters begin with simple organic compounds, the aliphatic hydrocarbns, proceeds to alicyclic hydrocarbons and then goes on to the aromatic hydrocarbons. Many of the contributors to Volume 4 are well recognized for their research in the area of organic compounds.  Volume 5 continues the complexity of the organic compounds with chapters on halogenated hydrocarbons, aliphatic carboxylic acids, ethers and aldehydes. These chapters have been updated from previous Patty's editions.  Volume 6 contains chapters on ketones, alcohols, esters, epoxy compounds and organic peroxides.  Volume 7 continues the coverage of the toxicology of organic compounds including polymers, polyurethanes, glycols, organic sulfur compounds and organophosphate compounds (pesticides). All chapters are significantly revised and updated from previous Patty's editions.