Guidelines on the Ship-Board Odourisation of LPG

These guidelines were produced following notification to the SIGTTO Secretariat of several potentially dangerous incidents involving odourants. Detail is given on personal, environmental and business risk management. The capabilities and limitations of odourant injection equipment are also included. These guidelines should be written into charter parties when shipboard odourisation is to take place.

A number of incidents involving potentially dangerous practices aboard ship have been brought to the attention of the SIGTTO Secretariat. These incidents required crew to introduce an ‘odourant’ into ‘unstenched’ LPG cargoes. Examples of cases reported by SIGTTO members can be found below.

In 1987, a member of the working group that produced these guidelines was visiting a small, pressurised LPG carrier in the Far East. During his visit he had to persuade the Chief Engineer of the ship, clad only in shorts, not to decant odourant from a drum and inject it into the cargo tank with a semi-rotary pump, through a plastic hose.

In 1993, at a small LPG terminal in North West Europe that imported feedstock for a butane-air plant supplying domestic and industrial consumers, a drum of ethyl mercaptan odourant started to leak. The utility company was inundated with reports of gas leaks, to the extent that their inspection teams could not cope. This incident was complicated by the fact that during this period, a house in the area suffered a gas leak that resulted in an explosion, luckily without fatalities.

In 1997, a ship owning member of the Society was asked to carry out cargo odourisation on one of his ships, with ethyl mercaptan being supplied by the receiver. The odourant was supplied in standard 40 gallon (209 litre) drums and the discharge port was in the tropics. Within a short period of time the high ambient temperature caused the drums to bulge due to the build-up of internal pressure. Only prompt action by the ship’s staff, in rigging a water spray to cool the drums, prevented them from rupturing.

In 1998, the Master of an LPG carrier, time chartered to a major oil company, was asked permission for terminal staff to board the ship and odourise the cargo during discharge. A senior manager of the company was concerned about the equipment intended for use and vetoed the operation. The cargo was discharged un-odourised.

As a result of these and other incidents being drawn to the attention of the SIGTTO Secretariat, a fact finding meeting was convened. This meeting consisted of concerned members of the LPG shipping industry. Their investigations revealed that the practice of requiring ships’ crews to undertake odourisation was widespread and frequently undertaken with little or no understanding of the potential hazards to personnel and the environment.

It should further be recognised that the practice of shipboard odourisation often exposes the cargo owners and receivers to considerable business risk.

1. Background

2. Types of Odourant

3. Transportation and Storage of Odourant

4. Risk Management and Safety

5. Design, Operation and Maintenance of Odourant Injection Equipment

6. Training

7. Glossary of Terms

Appendix 1 Chemical Data Sheets

Appendix 2 List of Training Organisations

Appendix 3 Incident Scenarios and Consequence Analyses

Appendix 4 Informative References

SIGTTO

The Society of International Gas Tanker and Terminal Operators (SIGTTO) is an international body established for the exchange of technical information and experience, between members of the industry, to enhance the safety and operational reliability of gas tankers and terminals.

https://www.sigtto.org/about-us/