The Department of Homeland Security (DHS) has revealed a set of proposed regulations to improve security at high-risk chemical plants across the U.S, with draft regulations made available for public comment until 7 February 2007.

The aim is to prevent toxic attacks on US plants, which could have devastating effects on the public. Nevertheless, plant managers, state officials and other groups, according to Russ Knocke, spokesperson for DHS, have raised concerns.

Some state lawmakers have already introduced stricter chemical security rules but the federal rules take precedence. This means that states, such as New Jersey, will have its chemical security weakened, according to New Jersey Governor Jon Corzine.

"Federal standards are necessary. But federal rules must not 'limit states' abilities to take further action to protect our own citizens," said Corzine.

DHS has lined up few requirements, such as securing the perimeter, controlling access, preventing internal sabotage and discouraging pilfering of potentially dangerous chemicals. The security strategies that will be employed depend on the risk category of each chemical plant.

But the classification system is not clear enough to determine which plants belong to the high-risk categories, according to Jack Gerard, president of the American Chemistry Council.

Chemical plants are required to carry out an online risk assessment to find out their level of risk category. If termed high-risk, plants are required to go through vulnerability assessments and put forward a security plan.

Chemical companies are advised that non-compliance carries a $25,000 daily fine or may lead to a complete facility shutdown.