TOXICOLOGY, SAFE PRACTICES ON BOARD, PERSONAL PROTECTION

TOXICOLOGY, SAFE PRACTICES ON BOARD,

PERSONAL PROTECTION

To ensure safety on board one must adhere to the following points: Knowledge, training and strict routine. Knowledge of the cargo to be loaded, knowledge of your ship and her equipment; training in the use of safety equipment on board; strict routines in cargo handling, tank cleaning, strict routine in command and reporting, strict routine in using protective clothing etc.

Poisoning and other risk with cargo contact

Different chemicals affect the human body in many different ways. The subject is comprehensive and a deeper insight in to this is beyond the scope of this book. A general information and some practical advice will be given, however. Reference is given to Appendix , being an extract of 'Medi cal first aid guide for use in accidents involving dangerous goods' published by IMCO, WHO and ILO ref (36).

The definition of 'poisonous' and classification of poisons is not uniform throughout the world. We can define a poison as a substance which is harmful to human beings (or environment). In the IMCO Code ref (25) a substance is classified as a poison if there is a risk of death or serious bodily harm after oral intake, inhalation or skin contact.

The 'poisonousness' of a substance is usually expressed in terms of LD 50‑ values, Lethal Dose (sometimes LC 509 Lethal Concentration). These values are determined by tests with animals and give the dose, expressed in mg/kg body weight, which kills 50 % of the animals in a test series. This figure gives a rough indication of the degree of toxity of a substance. Various species of animals have different sensitivity, which gives some problems in applying the results to human beings. Examples of LD 50 values (pesticides of three categories):

Class  LD Substance

125 mg/ kg body weight paration  (pesticide)

125‑1500 - //- malation // -

3 1500‑2000 - // - bromofos - // -

In industry the effect of long time exposure of low concentration to a substance is of prime concern. The expression used is TLV (.1hreshold Limit Value), previously called MAC (Max Allowable Concentration). The TLV‑value expresses the concentration of a substance in air, in ppm (parts per 3 million) or mg/cm , which must not be exceeded if a daily 8‑hour exposure over a long period of time shall be harmless.

TLV‑values are published by National Authorities and various organizations. The most recognized list of TLV‑values is probably the one published by ACGH (American Conference of Governmental Hygienists

ref (15). The ICS‑Guide ref(1) also gives TLV‑values. The gas concentration can be measured by means of a portable apparatus described in 3. 10 (Drager, Auer). The scale of reference for gas exposure on board is normally TLV ‑values. Human beings can, however, tolerate a significantly higher concentration in a short time exposure:

Substance  Danger of serious TLV

poisoning after (Swedish 1978)

less than one hour

inhalation

Acrylonitrile  100 ppm 2 ppm

Trichlorethylene  250 pprn 20 ppm

Carbontetrachloride  2000 ppm 2 ppm

Methanol 2000 ppm 200ppm

Benzene  10000 ppm 5 ppm

A person who is tired or ill is more sensitive than others and should not be asked to work with cargo handling.

It is a good safety practice to use a breathing apparatus whenever the TLV‑value in the atmosphere is exceeded

Poisoning

The poison may enter the human body orally, by inhalation, or by skin contact. After being absorbed by the body it may affect certain organs or give a general poisonous effect. Lately the cancerogene effects of some industrial chemicals have been noticed. This has led to significant reductions of hereto accepted TLV‑ values in many countries. Certain substances affect the tissues locally as an irritant (cashew nut shell oil) or cause grave damage to the eyes, skin or mucous membranes (e g strong acids and caustic). Other substances may be absorbed by contact to the skin without local effects (e g nitrobenzene, aniline). Gases, in themselves non‑poisonous, may be dangerous by their displacement of air (e g nitrogen as an inert gas in cargo tanks). The effect of a substance also depends on the temperature, its solubility in water or (skin) fat, its volatility etc.

Chlorinated hydrocarbons (e g tetrachloride and chloroform) may cause damage to kidneys and liver after prolonged exposures.

Symptoms of poisoning may appear many hours after contact with the substance. Typical examples are poisoning from nitrous gases, see 3:05, and methanol ( oral intake). The reason for the delay being that the decomposition products rather than the original product are toxic. Common symptoms of poisoning are: nausea, headache, dizziness, difficult breathing, unconsciousness.

The human body often reacts very differently to acute and chronical poisoning. (Acute poisoning ‑ one contact with the poison, usually high dose or strong concentration. Chronical poisoning ‑ small doses or low concentrations over a long time). E g benzene causes reduced conscoiusness in acute poisoning but causes blood and bone marrow damage in chronical poisoning.

Certain chemicals may cause sensitizing upon first contact. Later contacts with the same chemical, even at lower concentrations, may cause much stronger poisonous effects. Typical in this respect are isocyanates ( e g toluene diisocyanates) where astmathic ‑affects on sensitized persons may occur below TLV‑ value.

First aid

All cases of poisoning, regardless of which kind of poison, require certain basic common methods of treatment. Additionally, a few particular cases of poisonous substances may require antidotes. See Appendix 7 for detailed information on first aid for the various products!

After a severe acute case of poisoning involving unconsciousness: Bring the patient as soon as possible out into the fresh air. Rescue personnel must not take undue risks themselves, don't therefore rush down into tanks or pumprooms where vapour may be present‑ Too many fatalities have occurred with people who have not realised that a breathing apparatus was needed. First, keep the breathing passages free (prevent the tongue from falling back). An unconscious person should be laid on his side, face down, with one arm and one leg bent to prevent him from rolling over. Loosen the clothes around the neck and waist and remove false teeth, see fig 39.

Mouth to mouth artificial breathing may be necessary (avoid mouth to mouth contact with severely poisoned or contaminated patients as the rescuer may then be at risk). Heart massage may be necessary. See Appendix 7 for detailed advice.

If the patient's condition does not apparently involve immediate risk for his life the following measures are

applicable

After inhalation: The patient to be brought into fresh air with as little effort and strain to himself as possible, Undue strain on the patient may affect him adversely later. Even if the patient is free of all symptoms he should be kept quiet and rest as some gases have delayed effects (nitrogen oxides in combustion inert gas, nitrous gases). Keep the patient in a comfortable inclined sitting position (if unconsciousness does not prevent it).

After splash in the eyes: Immediately wash the eyes in gently flowing water, in a washbasin, in a jug or a special plastic eye bath with a bottle of water, see fig 40. The eyelids may have to be forced open and the patient told to move the eyes in order that all parts will be thoroughly rinsed out. Washing out the eyes may be very painful and pain‑relief eye drops can be used. Continue to wash for another 10‑15 minutes. In case of acids or alkalies (caustic) the washing must be repeated for a couple of minutes every 15‑30 min for the next 4‑5 hours, preferably with a NaCl (table) salt solution (0, 7 ‑ 0, 9 %). A sterilising eye ointment should be applied several times during the day. In case of acids and alkalies: obtain medical advice!

After skin contact: Regardless of product the area should be rinsed liberally with water, clean sea water can be used.Soiled clothes, rings, watches, shoes etc must be taken off. Wash the area thoroughly with soap and water. Also products which do not disolve in water will be partly removed by washing in soapwater. (Poison dissolved in the skin fat will then be washed off).

After swallowing: If the patient is unaffected give him a couple of glasses of liquid to drink for dilution of the poison, preferably water (never any alcoholic drink). After intake of alkalies (caustic) a drink of lemon juice can be given, or a 1 '76 solution of acetic acid. If available give medicine coal which absorbes a number of poisons and which in itself is harmless (30‑60 crushed coal tablets or coal granulate in some water). Make the patient vomit, NOT, however, in the case of corroding (acids or caustic) products or oil products like kerosenes, gasoline, jet fuels, when vomiting may be life‑threatening. Dilution of the stomach contents, however, is important. In case of doubt: do not cause the patient to vomit.

Vomiting can be caused by giving warm salt water (one table spoon of salt to one glass of water). Then by putting two fingers down the throat and moving them about gently vomiting usually follows. The procedure is described in ref (36).

After certain products antidotes should be given, see advice in ref (1) and (36). The most likely cargo for which an antidote may have to be used is acrylonitrile ('AN') and acetone cyanohydrine. The remedy then is to douse some clean rag with an ampoule of amyl nitrite from the medicine kit and hold it under the patient's nose 5 times with 15 s interval.

Oxygen should be administered in cases of weak breathing. It is an IMCO Code ref (25) requirement to have oxygen resuscitation equipment on board.

In cases of poisoning medical advice should be sought as soon as possible, e.g through the various radiomedical' services. While at sea also contact the shipper, who usually possesses a good knowledge of the product and its after effects.

Cargo information to ships personnel

The following advice is more or less obvious but is listed for the sake of completing the above information.

It is a clear responsibility for the Owner, the master and the officers to inform their personnel about the cargoes to be carried, safety procedures etc and to arrange for the proper training.

Information should be given partly in the form of written notices combined with informal meetings with the entire crew present when new cargoes are to be loaded or when unexperienced personnel are to be signed on. Among other things the following information should be given:

- Cargoes to be loaded; their characteristics as regards handling, pumping, toxity, corrosiveness, first aid etc

- the cargo loading plan to be posted in places where it will be clearly seen by everyone on board and at the accomodation ladder, when in port.

- Post cargo information cards for products to be loaded or are contained on board. One suitable type of card can be found in ref (i), with examples in fig 43. Also ref (4) and (5) show suitable information. For 'new' products ask the shipper for safety brochures and leaflets. See also ref (3), (12), (13), (16), (17) and (28).

- the personal safety equipment to be used by those involved in cargo handling, pumping, sampling etc.