The proposed system, which will be discussed with the states, will be based on "scores" that industrial units will be given on the basis of these pollution-related parameters. The new classification is part of the ministry's effort to put in place a system that is responsive to environmental challenges while providing industries with a more conducive set up. The proposed classification will be on the basis of a composite score — comprising 40% weightage for air pollution, 40% for water quality and 20% for nature of waste.

The parameters will include toxic pollutants, besides the standard basket of particulate matter, sulphur dioxide, nitrous oxide, benzene, ammonia, the pH (to ascertain the level of acidity of water quality), total suspended solids and level of dissolved oxygen. Industries that score more than 60 will be classified as red, those from 30 to 59 as orange, from 15 to 29 as green while units with less than 15 will be considered as non-polluting.

Consent to operate will be specified for a time limit, after which there will be a review —red category industries will be given consent for five years and orange for eight. Green categories will require a one-time consent for the life cycle of the unit, while nonpolluting industries will not require any consent.

Industries are currently classified into three categories in decreasing order of severity of pollution — red, orange and green. Introduced in 1989, this system was geared to link the pollution potential of industries at a particular location to help people understand the severity of pollution from a specific industry. Given the location-specific component, it is not possible to have a uniform classification throughout the country, although the Central Pollution Control Board has tried to harmonise the industries in the three categories.

The environment ministry is of the view that the present system does not take into account sectorspecific plans for controlling pollution and instead classifies industries and industrial activities on the basis of size, manpower and consumption of resources.

The view in the ministry is that pollution parameters and their impact on health are not considered primary criteria in this classification. The ministry has proposed that no red-category industries will be permitted to set up units in urban, eco-sensitive and protected areas.

The classification of industries will be undertaken by a team comprising officials for the central pollution board, state boards and the ministry.

Experts say a dynamic classification that takes into account the actual levels of pollution of an industrial unit and the carrying capacity of a particular area is preferable. However, the efficacy of the proposed system will depend on the manner in which it is implemented and monitored.

The proposed classification will be on the basis of a composite score — 40% weightage for air pollution, 40% for water quality and 20% for nature of waste.