The Offshore Chemical Notification Scheme (OCNS) applies to all
chemicals used in the exploration, exploitation and associated
offshore processing of petroleum on the UK Continental Shelf.
It incorporates "operational"
chemicals/products* which, through their mode of
use, are expected in some proportion to be discharged. This
includes rig washes, pipe dopes, jacking greases and hydraulic
fluids used to control wellheads and blow-out preventers.
As well as those chemicals used in the actual production of
hydrocarbons, those generated offshore (such as sodium
hypochlorite) must also be notified.
Default product templates for these types of chemicals are
available in our Downloads section.
* The word "chemicals" when used
subsequently refers to fully formulated products used offshore,
whether these are comprised of one or more distinct chemical
Chemicals not covered
The scheme does not apply to chemicals that might otherwise be
used on a ship, helicopter or other offshore structure. Products
used solely within domestic accommodation areas - such as additives
to potable water systems, paints and other coatings, fuels,
lubricants, fire-fighting foams, hydraulic fluids used in cranes
and other machinery - are also exempt.
If there is any doubt
about whether or not a chemical should be included in a UK risk
assessment, then operators are advised to consult the UK's
Department of Energy and Climate Change or Cefas. All queries
regarding risk assessment in the Netherlands should be directed to
State Supervision of Mines.
How does the process work?
Our OCNS team conduct work for both the UK and the Netherlands,
using the Chemical Hazard and Risk Management
(CHARM) model as the primary tool to rank offshore
chemicals according to their calculated Hazard Quotients (the ratio
of Predicted Environmental Concentration (PEC) to Predicted No
Effect Concentration (PNEC)).
Inorganic chemicals and organic chemicals with functions for
which the CHARM model has no algorithms are ranked using the Cefas
OCNS hazard groups.
All products currently registered by Cefas for either the
Netherlands or the UK are presented on the ranked lists. The lists
use a banding system to rank organic chemicals of similar function
according to the Hazard Quotients.
The minimum data set of actual values and the parameters used by
Cefas to calculate them will be disclosed to chemical suppliers on
"templates". The supplier may then pass these on to operators to
enable the calculation of site-specific risk assessments for any
chemicals they may want to use. Some chemicals are generated/used
in situ on offshore installations, e.g. sodium
hypochlorite, and don't fall under the remit of any one supplier.
Templates for such chemicals are available in our downloads
Once classified, a product will typically remain on the List of
Notified Chemicals for three years after which it becomes due for
re-certification. However, products being used for a field trial or
those containing substances recommended for substitution may have a
shorter validity. When products are due for re-certification, a
full Harmonised Offshore Chemical Notification Format (HOCNF)
registration form and SDS must be resubmitted.
Web links for OSPAR, the relevant regulators, Marine Scotland
and others may be found in our Downloads section.