During its thirty-first session in 2026, the International Seabed Authority continued work on the standards, environmental thresholds and regulatory arrangements required before exploitation can begin. In July, the Legal and Technical Commission reported further progress by the expert group developing binding environmental threshold values. The resulting report will be subject to stakeholder consultation before recommendations are presented to the Council.
This work is important. Thresholds can provide measurable boundaries for environmental performance and support consistent regulatory decisions. However, compliance with a threshold does not necessarily demonstrate that all reasonably practicable measures have been taken to reduce risk.
That distinction brings the ALARP principle into the discussion.
ALARP is a decision process
ALARP means reducing risk to a level that is as low as reasonably practicable. It does not mean reducing risk until it falls within an acceptable category on a risk matrix.
A credible ALARP demonstration should identify the hazards, assess the possible consequences and consider available measures for eliminating or reducing the risk. It should show that recognised good practice has been applied and explain why any additional measure has not been adopted. Rejecting a measure normally requires evidence that its cost, difficulty or operational burden would be grossly disproportionate to the additional risk reduction achieved.
The ISA has already incorporated this thinking into its draft guidelines on hazard identification and risk assessment. The stated intent is to reduce the risk of incidents as much as reasonably practicable. The guidelines form part of a wider package covering environmental management systems, monitoring plans, safe operation of mining vessels and emergency response.
The lesson from offshore petroleum
Offshore petroleum experience shows why ALARP cannot be treated as a one-time calculation. Complex operations involve changing conditions, technical interfaces and assumptions that may prove incorrect.
An operator may complete a risk assessment, apply recognised standards and obtain regulatory consent. This does not transfer responsibility for the remaining risk to the regulator. The operator must continue to understand the risk, verify that the controls work and respond when operating experience or new information challenges the original assessment.
The same principle should apply to deep-sea mining. Approval of a plan of work by the ISA would confirm that the regulatory requirements for approval had been met. It should not be interpreted as the ISA assuming responsibility for the contractor’s operational or environmental risk.
Residual risk must have an owner
Some risk will remain after all reasonably practicable controls have been implemented. That residual risk must be clearly described and accepted at the appropriate organisational level.
This is particularly important where several organisations contribute to an integrated mining system. A vessel operator, subsea equipment provider, survey contractor and environmental monitoring team may each control part of the operation. Risk can easily disappear between contractual and technical interfaces unless responsibilities are explicit.
Formal acceptance should therefore identify who owns the risk, what assumptions support the decision, which controls are critical and what would require the decision to be reconsidered. Significant residual risk should not be accepted by someone without the authority, competence or information needed to understand its consequences.
Sponsoring States also have an important oversight role, but their responsibilities are different from those of the contractor. Regulatory supervision should test whether risks are properly assessed and controlled. It should not replace operational ownership.
ISO provides the management-system structure
ISO 31000 supports this approach by placing risk management within governance, leadership and decision-making. It emphasises risk treatment, monitoring, communication and review rather than treating the assessment as a completed document.
ISO 14001:2026 provides a complementary environmental management framework. Its focus on operational control, compliance, evaluation and continual improvement can help convert environmental commitments and ISA requirements into managed operational processes.
These standards do not determine whether a specific deep-sea mining risk is acceptable. They can, however, help ensure that the decision is structured, documented and reviewed.
Acceptance is not the end of responsibility
An ALARP conclusion remains valid only while its assumptions, controls and supporting evidence remain valid. New environmental data, equipment changes, incidents or improved control technology may all require the assessment to be reopened.
For deep-sea mining, responsible acceptance of residual risk must therefore be understood as an ongoing obligation. The decision is not simply whether the remaining risk can be accepted today, but who will remain accountable for monitoring and controlling it tomorrow.
Bruncell Larsen Strategic Advisory supports organisations working with regulatory compliance, risk management and operational assurance in complex and emerging maritime activities. Please contact me if you would like to discuss these issues further.
