Category Assessment: whether a unit is Red, Orange, Green or White decides almost everything after.

It is the CPCB classification of industrial sectors by pollution potential, computed as a Pollution Index from air emissions, effluent, hazardous waste and resource consumption. Red covers the most polluting sectors, then Orange and Green, with White reserved for practically non-polluting activities. State Pollution Control Boards apply the same classification when processing consent.

The validity period of the Consent to Operate, the consent fee slab, the level within the Board that decides the application, the frequency of inspection and returns, and the applicability of siting restrictions. It can also determine whether online continuous monitoring is required. A wrong category therefore produces the wrong consent on every one of those dimensions.

White category activities are generally exempted from the requirement of consent, with an intimation to the State Board instead. The exemption is narrow and applies to the listed activity itself: if any Red, Orange or Green activity is carried on at the same premises, consent is required for the site notwithstanding the White listing.

The site is treated on the most polluting activity present. A minor ancillary operation carrying a Red listing pulls the whole site to Red for consent purposes, even if the principal product is Green. This is one of the most common sources of mis-categorisation, and it is best identified before the consent application rather than at inspection.

No. CPCB revises the categorisation from time to time, adding sectors and reassigning others as the index methodology and data are updated. A category settled at the last consent should be re-verified at renewal, because a sector can move without anything changing at the unit itself.

No, and conflating the two is a frequent error. Environment Clearance is triggered by the schedule to the EIA Notification 2006, by activity and threshold. The CPCB category governs consent under the Water and Air Acts. A Red category unit may need no EC, and a project needing EC may not be Red, the two determinations must be made separately.

The category follows the listed sector and the activity carried on, so it is not negotiable as such. What can legitimately change it is a correct characterisation of the process, for example demonstrating that the operation falls within a different listed entry, or that a higher-category ancillary activity has been discontinued. That case has to be made on process evidence to the Board.