DERATING OF SHIPS

•    Hydrogen cyanide is used for deratting by fumigation process.
•    Sulphur dioxide can be used if Hydrogen cyanide is not available.
•    Deratting of Ships is usually carried out by specialized agents under supervision by Port Health Officers (Members of Competent Authority).
•    At the end of successful deratting operation, a Deratting Ship Sanitation Control Certificate is issued to the Master of the Ship by Port Health Officers.
•    Ship Sanitation Control Certificate is valid for six (6) months.
•    When the Ship Sanitation Control Certificate expires, Master of the Ship or the agents must request for renew in the first Port of embarkation approved for issuing the Certificate.
•    If the Ship is returning to the home Port, the Master of the Ship can request permission to have fumigation deferred until then.

Hydrogen cyanide fumigation;
•    Fumigation for deratting by using Hydrogen cyanide is 56 g per 28 m3 of space treated.
•    Fumigation for deratting using Sulphur dioxide is 1.34 kg for 28 m3 space treated.
•    Time period for fumigating using Hydrogen cyanide is two (2) to six (6) hours depending on the nature of the ship.
•    In heavy infestation, the dose of Hydrogen cyanide fumigation can be from 112 g to 167 g of Hydrogen cyanide per 28 m3.
•    During fumigation using Hydrogen cyanide gas, the Ship must be completely covered to avoid gas to escape.
•     Hydrogen cyanide is colourless gas which liquefies at 13.80C and boils at 26.10C.
•    Hydrogen cyanide is normally employed as liquid that is readily converted to gas.
•    Hydrogen cyanide liquid is either sprayed at a given pressure, or absorbent materials impregnated with cyanide or gaseous spray at a given pressure, giving out a fine cloud gas.
•    After completing fumigation, tests for the presence of Hydrogen gas should be carried.
•     The Ship must be free from Hydrogen cyanide gas before being occupied.
•    Hydrogen cyanide is a protoplasm poisoning, arresting activities of all forms of living matter by stopping oxidation and suspending vital functions.
•    Sodium monofluroacetate known by the American Chemical formula 1080 is a new Rodenticide which can replace both Hydrogen cyanide and Sulphur dioxide.
•    Hydrogen cyanide may access to the body by absorption through the skin, inhalation of the gas and ingestion of contaminated food or drink.


Signs and symptoms of Cyanide poisoning;
•    Irritation of the throat and nose. 
•    Restricted breathing.
•    Dulling of the senses with local anaesthetic action on the portion of the body affected.
•    Watering of the eyes.
•    Headache and weakiness of limbs
•    Vomiting and violent headache.
•    Slow pulse and difficult breathing.
•    Short inhalation followed by long inhalation.
•    Pale face and collapse.
•    Severe shock with violent muscular reaction.
•    Intermittent breathing followed by death.

Incubation period;
i.    It ranges from 2-3 days,
ii.    Fatal dose of Hydrogen cyanide is 16 mg.

First Aid;
i.    Patient should inhale Amyl nitrate.
ii.    Cyanide antidote of a mixture of 158 g Ferrous sulphate crystals and 60 g Anhydrous Sodium carbonate in water and give to the patient immediately.