Identifying Hazards and General Precautions


CTM 9.2	Chemical Tanker Manual CTM Identifying Hazards and General Precautions	Doc No.: CTM 9.2 Revision: 01 Date: 15 Oct 2024 Issued by: DPA Approved by: MD

1 APPLICATION

This document applies to all Chemical Tankers managed by Company.

2 PURPOSE

The purpose of this document is to inform about possible hazards when operating chemical tankers, and to provide relevant precautions associated with such hazards.

3 IDENTIFYING HAZARDS OF CHEMICAL CARGOES

3.1 General

Carriage of Chemical Cargoes is different from any other liquid bulk transportation as:

Many cargoes of different properties/ hazards may be carried simultaneously.
Operations such as loading/discharging/tank cleaning may run concurrently.

Note:

Knowledge of the physical and chemical properties, hazards and response action to be taken in the event of emergency is essential for the safe and efficient carriage and handling of chemical cargoes.

3.2 Hazards of Chemical Cargoes

Cargo Flammability (Fire/Explosion)
Chemical Hazards:

Chemical Reactivity – Reaction with -

Self (Polymerization)
Air (e.g., Peroxides)
Water (e.g., Sulphuric Acid, Isocyanates)
Other cargoes (Cargo Compatibility)
Other materials (Material Compatibility)

Corrosiveness of cargo (destroy human tissue)
Toxicity (damage living tissue, illness)
Anesthesia (loss of consciousness)
Putrefaction (Veg Oils decomposition)

For detailed description of the Hazards See CTM 9.2 Appendix 1 – Hazards of Chemical Cargoes - Description

3.3 Cargo information

Note:

To identify the hazards of the chemical cargoes correctly it is important that the correct technical name of the cargo is known.

Master shall obtain the following from Shippers (or Other Relevant parties) for the cargo to be loaded:

Correct technical chemical name
Material Safety Data Sheet (MSDS)
Sufficient additional information required for its safe and efficient carriage (If the cargo is not adequately covered by the MSDS)
Additional Sources of Cargo Safety Information available on board

USCG Chemical data guide for bulk shipment by water (CHRIS Code)
Milbros or Alternative Company Approved Software

Master and all those concerned shall use the data sheet and/or any other relevant information to familiarize themselves with all characteristics of each cargo to be loaded.

Warning:

If relevant information essential to safe and efficient carriage of cargo is not available, do not proceed with the loading of the cargo. Inform Marine Department and seek instructions.

Note:

Prior to discharge Master must hand over a copy of the MSDS to the terminal representatives and advise all persons coming on board the vessel of the hazards concerned.

4 PRECAUTIONS IN GENERAL

While MSDS and other sources as described above would provide specific precautions for each cargo, some general precautions are mentioned below:

4.1 Chemically Reactive Cargoes

Self-Reactive Cargoes Officer(s) in charge shall:

Ensure that the pipelines or tanks do not contain any materials which are identified as unsuitable on the data sheets.
Closely monitor the temperature during the voyage.

Be aware of:

Effect of heat on such cargo and ensure stowage is not next to heated cargo.
Emergency procedure should a cargo start to self-react.
Whether the inhibitor is oxygen-dependent, and if so, minimum oxygen content needed.

Cargoes which react with Air

Such cargoes shall be carried either inhibited or under inert condition.

Cargoes which react with Water

Coution:

Pay caution when tank cleaning.

Refer to specific Tank cleaning guidelines from Milbros. This may include:

Using an alternative washing medium
Using water with a very specific procedure e.g., using copious amounts of water initially to bring the concentration down.
Certain cargoes need to be carried in a dry and inert condition.

Cargoes which react with other cargoes

Use Compatibility tables to ensure that segregation if required is always maintained.

Cargoes which react with other materials

Officer(s) in charge shall ensure:

The material of construction of the tank and associated equipment is compatible with the cargo carried.
Material compatibility is checked prior to introducing any equipment into the tank.

4.2 Corrosive Cargoes

All personnel involved in handling corrosive cargoes must:

Avoid contact with cargo.
Wear proper Personal Protective Equipment (PPE) when there is a possibility for contact.

See FOM 10.10 Personal Safety

4.3 Toxic Cargoes (CDI 5.5.9)

Master/ Officer(s) in charge shall ensure -
Notice is displayed at the access point to the vessel and at the other conspicuous places stating:

Note:

"WARNING - TOXIC CARGOES BEING HANDLED”
“NO VISITORS”
“ACCESS TO MAIN DECK ONLY PERMITTED TO PERSONS AUTHORIZED BY THE MASTER”

All personnel wear proper PPE when there is a possibility for exposure, including but not limited to use of:

SCBA
Full chemical suit

Some examples are:

Inspecting pipeline and machinery for leaks
Dealing with accidental leaks and spillage
Connecting / disconnecting hoses and loading arms
Taking ullages and samples
Entering enclosed spaces such as pump room
Opening up pumps and equipment

Warning:

Filter type respirators shall not be used for cargoes identified as toxic by the code on the MSDS, nor should they be used in place of a breathing apparatus.

See FOM 10.10 Personal Safety

Coution:

When corrosion takes place, there is a release of hydrogen gas, which is highly flammable.
Contact with fibrous materials such as cloth, sawdust, etc. may in some cases cause ignition of the material. Some corrosive liquids are also combustible. Follow precautions that include adequate ventilation of space and control of ignition sources accordingly.

Appropriate gas detector is used for gas detection.

Arrange for checking of:

All emergency escape sets on prior to arrival at berth.
Entire cargo system for tightness prior to operations.
Atmosphere in cargo deck area

Note:

Most chemical vapours are heavier than air and tend to flow along the deck and may possibly accumulate at low spots - e.g. below pump room floor plates.
Give emphasis to low areas, where concentrations are likely to be the highest

Chief Engineer shall:

In case of any leakage of cargo or vapor, and during venting operations, arrange for the air conditioning system of the vessel to be put on recirculation.

Coution:

Some cargoes which may not be toxic when loaded may end up so.
Most animal and vegetable oils undergo decomposition overtime. This generates obnoxious and toxic vapour and also depletes oxygen.
Similarly, certain other cargoes may react dangerously with air on water on other cargoes / materials to release toxic vapour

Note:

If loading Benzene or benzene containing mixtures, Naphtha and white spirit, refer to MSC 1095. Also See Annex 011.

4.5 Putrefaction

Tanks that have contained animal and vegetable oils products must be properly ventilated and the atmosphere tested prior to tank entry.
This is especially important prior to sending personnel into the tank for sweeping purposes.

4.6 Static Electricity

Due to the presence of static electricity, fire and explosion hazards are present during the handling of petroleum and other static accumulator liquids.
Critical operations are tank cleaning, start of loading, dipping, ullaging and sampling.
The main protection for tankers against static risks is to conduct operations with the cargo tanks protected by Inert Gas.

For a list of Static Accumulator cargoes, see CTM 9.2 Appendix 2 - List of Static Accumulator Cargoes

5 OTHER SAFETY ASPECTS

5.1 Personal Protective Equipment (PPE)

All crew and officers who may be exposed to any hazard shall wear relevant PPE as per FOM 10.10 Personal Safety.

5.2 Enclosed Space Entry

For entry into cargo / ballast / bunker tanks and void spaces or any other enclosed space, follow instructions as laid out in FOM 10.13 Permit to Work systems.

5.3 Checking of Ballast Tanks and Void Spaces

Officer(s) in charge shall:

Closely monitor all ballast tanks and void spaces to ensure:
- They are free of cargo and cargo vapours.
- There is no increase in ullage / soundings.
Have the following checks carried out:
- Ballast tanks soundings
  - Daily
  - In case of any unusual occurrence, e.g., unexpected list, operational problems.
- Atmosphere checks of ballast tanks, void spaces, and deck houses on forecastle and main decks
  - At least once a week or more frequently at Master’s discretion, subject to cargoes carried.
- Additional atmosphere checks:
  - Prior to ballasting the tanks after a period of heavy weather.
  - Before any tank entry.

Note:

Record the results in the separate Log.

5.4 Vapour Return System

Note:

Applicable for cargoes requiring vapor return system as per IBC (15.12.2)

Master shall:

Ensure cargo operations are conducted as per vessel-specific Vapor Return Manual.
If terminal is not able to provide vapour return,
consider the implications and risks of exposing the crew to the vapours.

Note:

Consult Marine Department and take measures to prevent exposure

Warning:

If Master believes it will not be possible to take adequate measures, he shall not allow the cargo operations to commence and notify the Operator immediately.

In all cases, issue a Letter of Protest to the terminal for the lack of vapour return.
Arrange for:
- Proper vapour drop calculations to be made and shared with the loading Master.
Where the vapour collection arrangements are combined with other cargo tanks, ensure:
- Stop valves or other acceptable means are provided to isolate each cargo tank.
Where stop valves are fitted, ensure:
- They are provided with locking arrangements.
- These are under the control of the ship’s responsible officer.

Note:

Ensure there is clear visual indication of the operational status of the valves or other acceptable means to check their actual status.

Coution:

Do not increase tank pressure beyond what is allowed by terminal as many vapour recovery system shut off loading if pressure increases beyond their tolerance.

6 MEDICAL FIRST AID

6.1 Publications

Publications which give advice on dealing with exposure to toxic cargoes are:

International Medical Guide for Ships (IMGS)
Medical First Aid Guide for Use in Accidents Involving Dangerous Goods (MFAG).

The MFAG is supplementary to the IMGS and contains advice for recognising and treating chemical poisoning, within the limits of the facilities available on board.

6.2 Chemical Poisoning

Symptoms are unexpected headaches, nausea and vomiting, drowsiness, changes in mental behaviour, unconsciousness, convulsions, or pain.

During the handling of chemicals, if any person shows symptoms of poisoning, master shall:

Treat him in accordance with the MFAG.
Arrange for him to be seen by a doctor as soon as practicable.
Seek medical advice by radio, if still at sea.

Note:

Assistance may also be available from another ship with a doctor on board.

Note:

Section 4 of the MFAG gives directions on how to recognize the general symptoms of poisoning. They may not appear for some time after exposure to the chemical.

Warning:

If the patient has a rapid but weak pulse, a greyish blue colour of the skin, severe breathing difficulty or remains unconscious for a prolonged period, severe poisoning must be suspected and immediate medical assistance must be provided.
In such cases, Master shall contact Marine Department for guidance and instructions.

7 APPENDICES

CTM 9.2 A1 Hazards of Chemical Cargoes – Description
CTM 9.2 A2 List of Static Accumulator Cargoes