The precautionary principle is accepted in India as a fundamental tool to promote sustainable development and is employed within Indian environmental governance to promote better health a he role of the Supreme Court of India in recognizing the precautionary principle as an essential feature of sustainable development and a part of customary international law promoted its derivative application from constitutional mandates namely Articles 21, 48A and 51A(g).11 In 1996, Kuldip Singh J in Vellore Citizen Welfare Forum v Union of India 12 declared that the principle involves three conditions:
State government and statutory authorities must anticipate, prevent and attack the causes of environmental degradation.

Where there are threats of serious and irreversible damage, lack of scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation;
The onus of proof is on the actor or developer or industrialist to show the actions are environmentally benign.

Additionally, the specialized environmental tribunal, NGT is a creation of a statute; its jurisdiction, powers and procedures are construed and applied according to the language of the National Green Tribunal Act 2010. The NGT interprets and applies the precautionary principle as mandated by s. 20 of the National Green Tribunal Act 2010.13

The NGT declared the precautionary principle to be an integral part of national environmental law:
The applicability of [the] precautionary principle is a statutory command to the Tribunal while deciding or settling disputes arising out of substantial questions relating to environment. Thus, any violation or even an apprehended violation of this principle would be actionable by any person before the Tribunal. Inaction in the facts and circumstances of a given case could itself be a violation of the precautionary principle, and therefore bring it within the ambit of jurisdiction of the Tribunal, as defined under the NGT Act 2010.14

The NGT regards the precautionary principle as a determinative norm that allows the judges to examine the probability of environmental degradation and resulting harm that may occur from a proposed activity. This involves well-crafted scientific knowledge supporting precaution and prohibition of harm and a commitment to dealing with risks.15

To activate precaution, actions are based on scientific information and analysis of possible risks to human health and environment, albeit tentative, inconclusive or in dispute. Tentative, inconclusive or disputed scientific information creates uncertainty in relation to gaps in data and/or poor data, ignorance, faulty models, scientific inconsistency and disagreement on the nature of risk with low epistemic threshold of evidence and tend towards risk prevention.16

The availability of merit review to the NGT promotes judicial application of the principle. As a merit court, the NGT becomes the primary decision-maker and can undertake in-depth scrutiny that involves not only law but also the technical evaluation underpinning a decision.17 The precautionary principle is invoked and followed by judicial and expert members as a normative commitment.

It thereby directs the judges, particularly the technical expert judges, to offer scientifically based structural solutions and policies that respond creatively to weak, ineffective regulation even in the absence of regulation. Adoption of a variety of procedures, including investigative,18 stakeholder consultation19 and appointment of specialised committees,20 helps in the application of the precautionary principle.

This improves active participation through dialogue, argument and norms for eliciting factual realities and expert knowledge to respond to environmental problems. Expert members by on-spot site inspection can evaluate contradictory claims, positions and reports filed by the parties.21 The stakeholder consultative process is applicable to cases of wider ramification involving major issues including river cleaning and air pollution.22 The specialized committees promote the accountability of different authorities for the implementation of the rules under the National Green Tribunal Act 2010.23

Thus, the precautionary principle in India mandates well-judged usage in favour of observing, preventing and mitigating potential threats. Indeed, modern risk factors have become more complex, far reaching and adversely affect public health and environment.

The principle is employed as a tool within Indian environmental governance to promote better health and environmental decisions. However, the principle is both controversial and difficult to apply due to its inconsistency (normative aspects) and misapplication (legal standard of proof). In the fourth section, these issues are addressed in the Indian context. nd environmental decisions.