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Measures against rats , mice & vermins- a brief safety guide for general cargo ship

Rats and mice

A rat consumes approximately its own weight in food per week, but the potential for loss does not end there. Edible goods which have been attacked by rodents usually have to be condemned as unfit for the purpose for which they were intended. Additionally, the cost of re-bagging, replacing torn bags with new, the loss of contents and damage to textile or leather goods, all caused by rats in their search for nest-making materials, may well result in large claims. The risk of fire, which their propensity for carrying oily rags into remote and ill-ventilated areas engenders, is considerable.

Rats carry diseases dangerous to humans either through their droppings or through a flea carried by the rat and most governments enforce strict regulations on vessels visiting their ports to ensure that any rats on board do not succeed in getting ashore. However, the ship is concerned with controlling the environment on board and the first line of defence is stopping them getting on board. Whether rat guards were originally intended to stop rats getting on board a ship or to stop them getting ashore from the ship, ships are now certainly seen by shore authorities as harbouring potential invaders.

Consequently, ships are likely to be fined for having improperly fitted rat guards because they "won't stop the rats getting ashore". However, whatever the reason, it is still important for the ship to have well-fitted rat guards. Without doubt, the most effective guards are circular, constructed of metal with a closing sector thus allowing the full circumference of the rope to be encircled.

Other precautions that may help prevent rats boarding a vessel are to keep the gangway well lit and lifted from the quayside if possible. Removing overside cargo nets at night may also help to deter rats from boarding. Refuse containers on deck should be kept securely covered.

However, should rats get on board, trapping and/or killing become necessary. This can be carried out using traps to capture them live or dead, laying poisons or, as a last resort, fumigation. The use of traps is preferable in that bodies can be collected and disposed of whereas rats killed by poison or fumigation may die in inaccessible areas and cause other problems as the body decomposes.

Chronic poison baits can be placed by ship's personnel ensuring that the manufacturer's instructions are followed and being careful when handling them. The poison is usually a cereal-based anti-coagulant which acts slowly as the rat eats the bait.

Rats die due to haemorrhages from small blood vessels which have been damaged in everyday life. Baits should be placed in rat runways and be protected from accidental consumption by humans or other animals and from contact with human and animal food. A record should be kept of where baits are placed and they should be searched for and removed from cargo spaces prior to loading of bulk food and livestock cargoes. Cereal baits should be replaced within 30 days to avoid insect infestation.

Acute poisons in baits or liquids must only be used in port and by qualified personnel. Such poisons may be put out at the end of a day as a liquid in pots which are left out overnight and collected in the morning with the treatment being continued for several days. The poison acts within a few minutes. Baits must be collected and disposed of when treatment is complete.

The International Health Regulations (2005) introduced new certification procedures for ships from June 2007 with Deratting and Deratting Exemption Certificates being replaced by Ship Sanitation Exemption Control and Ship Sanitation Control Certificates ("Ship Sanitation Certificates" or "SSC").

The SSC is used to identify and record any areas of ship-borne public health risks and has a validity of six months and may be renewed at any port authorised to issue such a renewal. It should be noted that the criteria for the issue of SSCs are somewhat more stringent than those previously required for Deratting Certificates.

A Ship Sanitation Control Exemption Certificate is issued when no evidence of a public health risk is found on board and the authority is satisfied that the ship is free of infection and contamination. Such a certificate can normally be issued only when the ship and holds are empty so that a thorough inspection can take place.

A Ship Sanitation Control Certificate is issued when evidence of a public health risk is detected on board and after control measures have been satisfactorily completed. The SSC must record the evidence found and the control measures taken.

An extension of one month to an Exemption Certificate may be granted if it is not possible to carry out an inspection or any required control measures in a port (e.g. due to the presence of cargo), thus allowing the ship to arrive at a port where a full inspection and/or any control measures can be carried out.

Smaller vermin

Various commodities may introduce vermin to the ship, the presence or ravages of which may prove costly.

Bales of rags, unless thoroughly fumigated, often harbour lice and other insects which, in turn, may be carriers of disease. Such cargo should not be accepted on board unless accompanied by a verifiable sanitary certificate which, in most cases, should be endorsed by the consul of the country of destination.

Certain tropical woods, particularly those used for dunnage, are apt to harbour ants, beetles and other insects which may be destructive to particular kinds of goods, wooden fittings, etc.

Other woods, mostly the hollow bamboo variety and old cord wood, are likely to host different species of cockroaches.

Timber dunnage from temperate regions may harbour eggs or larvae, so that many countries have developed strict safeguards and regulations to prevent the import of these insects. The Sirex Woodwasp, for example, is capable of decimating whole sections of fir forest and is most likely to be found in solid wood packing materials. It is native to Europe, Asia and North Africa but has been introduced inadvertently to many other countries.

The United States and Canada are particularly alert to identifying possible sources of infestation arriving by sea. Similarly, Asian Gypsy Moth is a subject of special interest to North American authorities and great efforts are made to identify ships arriving from high-risk areas (Far East Russia, Japan, South Korea and China) having loaded during designated periods when the Moth is active.

Ships arriving with infestation are likely to be denied entry to North American ports and it is sensible to obtain certification that the ship is Asian Gypsy Moth free prior to departure from the loading port.

Maggots, breeding in imperfectly cleaned animal products (e.g. hoofs, horns, bones, skins, etc.), will give rise to claims if infestation spreads to manufactured goods.

Some cereals and their flours, pulses, seeds, copra (kiln and sun dried), rice bran, meal and dust may be found to be insect infested­cereals and flour by weevils, copra by copra bugs, etc.

Dried blood shipped from Argentina, Australasia, etc., is prone to infestation by small beetles.



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