Offshore Chemical Management in Norway

Jul 10, 2026 | Resources

Offshore Chemical Management in Norway: HOCNF, NEMS and Discharge Permits Explained

Working with offshore chemical management on the Norwegian Continental Shelf, you’ll quickly come across terms such as HOCNF, NEMS, green and red chemicals, and discharge permits.

These are all part of Norway’s environmental management framework for offshore chemicals. Understanding how they fit together is essential for anyone working with chemical management, occupational hygiene, environmental compliance or HSE in the offshore industry.

This article explains how the framework works, how the different components are connected, and the role each plays in protecting the marine environment.

A Different Approach to Offshore Chemical Management

Norway’s approach to offshore chemical management is rooted in a long-term ambition to minimise the environmental impact of petroleum activities.

In 1997, the Norwegian Parliament adopted national zero-discharge targets for environmentally hazardous substances from offshore petroleum operations. Rather than prohibiting all chemical discharges, the objective was to eliminate or minimise discharges of substances that could harm the marine environment while encouraging the industry to replace hazardous chemicals with less environmentally harmful alternatives wherever possible. Over the following decades, this policy became one of the driving forces behind Norway’s environmental management framework for offshore chemicals.

The Building Blocks of the Norwegian System

Supporting this ambition requires more than simply knowing which chemicals are used offshore. Operators and authorities need consistent information about each chemical’s environmental properties, a common way of classifying environmental hazard, and a regulatory framework for controlling what may be discharged.

This is why Norway combines several complementary systems:

• HOCNF provides the environmental data
• NEMS manages and classifies the environmental data
• The Norwegian Environment Agency (Miljødirektoratet) uses this information when assessing applications for discharge permits
• Operators use the same information to ensure their offshore activities remain within the conditions of those permits.

Together, these elements create a transparent and consistent framework for protecting the marine environment while enabling offshore operations.

HOCNF: The Environmental Data Behind Every Assessment

Every environmental assessment starts with data. The Harmonised Offshore Chemical Notification Format (HOCNF) was developed by the OSPAR Commission to provide a standardised way of documenting the environmental properties of chemicals intended for offshore use. Rather than allowing suppliers to submit environmental information in different formats, the HOCNF defines exactly what information should be provided and how it should be presented. This allows operators and regulators across the OSPAR region to assess offshore chemicals using a consistent set of environmental criteria, regardless of who manufactures the product.

The HOCNF is normally prepared by the chemical supplier, who has access to the product formulation and technical information. Environmental test data is generated through laboratory testing using recognised international methods, while the supplier compiles the complete HOCNF documentation.

Importantly, an HOCNF is not an approval. It is the environmental data package used by operators and authorities to assess the potential environmental impact of offshore chemicals.

The Difference Between HOCNF and SDS

Why isn’t a Safety Data Sheet (SDS) sufficient? The answer is that the two documents have different purposes.

A Safety Data Sheet is designed to protect people. It provides information about hazards, safe handling, storage, transport, emergency response and occupational health in accordance with regulations such as REACH and CLP.

An HOCNF is designed to protect the marine environment. It provides the environmental information needed to assess the potential impact of offshore chemical discharges, including marine toxicity, biodegradation and bioaccumulation.

Because the two documents are developed under different regulatory frameworks and assess different types of risk, the same chemical may have different classifications in an SDS and an HOCNF. A product that presents relatively low risk to workers may still contain substances that persist in the marine environment or are harmful to aquatic organisms.

For this reason, an SDS alone is not sufficient for chemicals intended for offshore use on the Norwegian Continental Shelf. The HOCNF provides the additional environmental information needed for classification in NEMS and for discharge permit applications to the Norwegian Environment Agency.

The resulting colour category then helps operators determine whether a chemical can be used offshore within the limits and conditions of their discharge permit.

HOCNF and SDS Compared

NEMS: Turning Environmental Data into Practical Information

Once the HOCNF has been completed, the chemical supplier submits the environmental information to NEMS Chemicals, the industry’s shared database for offshore chemical information on the Norwegian Continental Shelf.

NEMS provides a common source of environmental information for operators and supports the registration, classification and management of offshore chemicals.

Before a chemical is made available to operators, the submitted HOCNF documentation undergoes quality assurance by the NEMS KPD Centre, an independent organisation responsible for verifying that the environmental data has been generated and documented in accordance with the applicable standards. This includes reviewing laboratory documentation and confirming that the required environmental testing has been performed using recognised international methods.

Once the HOCNF has been verified, NEMS calculates the Norwegian environmental colour category according to the criteria defined by the Norwegian Environment Agency. The verified chemical information is then made available to operators through the NEMS database.

Because all chemicals are documented using the same HOCNF format and verified through the same process, operators can compare products using consistent environmental criteria.

NEMS also protects commercially sensitive information. While authorities can access the full chemical composition where required, operators use verified environmental information without necessarily having access to proprietary formulations.

Understanding Norway’s Colour Categories

One of the most recognisable features of the Norwegian system is the environmental colour classification.

Using the environmental information contained in the HOCNF, NEMS automatically calculates the Norwegian environmental colour category according to the criteria defined by the Norwegian Environment Agency.

The colour categories provide a standardised way of communicating a chemical’s inherent environmental hazard and play an important role in environmental assessments, discharge permit applications and offshore chemical management.

The four main categories are:

• Green – Chemicals considered to pose the lowest environmental concern
• Yellow – Chemicals that are acceptable for offshore use but remain subject to environmental control
• Red – Chemicals that should be substituted where reasonably practicable and require stronger justification
• Black – Chemicals containing substances subject to the strictest environmental restrictions

A chemical’s colour category is based solely on its inherent environmental properties and does not change according to how much of the chemical is used. However, the planned quantity, intended application and expected discharge remain important factors when the Norwegian Environment Agency assesses the overall environmental impact of offshore activities and determines the conditions of a discharge permit.

Discharge Permits: From Application to Compliance

Unlike some regulatory systems, Norway does not approve offshore chemicals as individual products. Instead, operators apply to the Norwegian Environment Agency for permission to use and discharge chemicals as part of their offshore activities.

Preparing the Application

When assessing an application, the Norwegian Environment Agency considers information including:

• the environmental data documented in the HOCNF
• the chemical’s registration and classification in NEMS
• its environmental colour category
• the intended application and expected discharge volumes
• substitution assessments where required
• the overall environmental impact of the planned activities

The environmental colour category plays an important role during this assessment. It reflects the inherent environmental hazard of the chemical and helps determine how it should be managed within the regulatory framework. Green and yellow chemicals are generally easier to justify, while the use of red chemicals requires stronger justification and active consideration of safer alternatives. Black substances are subject to the strictest restrictions.

Operating Within the Permit

If the planned activities are approved, the Norwegian Environment Agency issues a discharge permit that establishes the conditions under which chemicals may be used and discharged during the operation.

From that point onwards, responsibility shifts to the operator. The operator must ensure that chemical use remains within the conditions of the discharge permit, that substitution requirements are addressed where applicable, and that actual chemical use and discharges are monitored and reported in accordance with regulatory requirements.

This means the discharge permit is not simply an approval issued at the start of an operation. It forms the legal framework for environmental compliance throughout the lifecycle of offshore activities, from planning and chemical selection to operational reporting.

Reporting and Continuous Environmental Management

Operators continue to record chemical consumption throughout offshore operations and calculate actual discharges based on how each chemical is used. This information forms the basis of mandatory environmental reporting and demonstrates compliance with the conditions of the discharge permit.

The same environmental information that supported the original assessment therefore continues to support environmental management throughout the chemical’s operational lifecycle, enabling both operators and authorities to verify that actual chemical use and discharges remain within the conditions of the discharge permit.

The Framework at a Glance

Although each component has a distinct role, they all support the same objective: protecting the marine environment while enabling safe offshore operations.

Rather than viewing HOCNF, NEMS, colour categories and discharge permits as separate requirements, it is more helpful to see them as interconnected parts of Norway’s offshore chemical management framework. Together, they provide a consistent approach to assessing, permitting, managing and reporting offshore chemical use on the Norwegian Continental Shelf.

Where does ChemCenter fit? ChemCenter helps operators integrate environmental information into their wider chemical management processes, supporting operator approval workflows, risk assessments, substitution, operational documentation and traceability throughout the chemical lifecycle. It complements the Norwegian offshore chemical management framework rather than replacing the specialised environmental assessments performed through HOCNF and NEMS or the discharge permit process administered by the Norwegian Environment Agency.