Appendix – General Requirements for Carriage of Ferrosilicon

1. Chapter II-2 of SOLAS requires fire-fighter's outfits, full chemical protective suits and self-contained breathing apparatus to be readily available on board.

2. Gas concentrations shall be measured, during the voyage, at least once during every eight hours at each outlet ventilator and in any other accessible space adjacent to the cargo space carrying this cargo and the results shall be recorded in the log-book. Facilities shall be provided to make accurate determinations of the gas concentrations at each outlet ventilator without danger to the operator.

3. Ventilation fans shall be in operation at all times from commencement of loading until the cargo space is free of ferrosilicon.

4. The bilge wells shall be in a clean, dry condition before loading. The bilge timbers shall be in good condition and covered with double burlap.

5. The bilge wells shall be opened up and the cargo space cleaned up after discharging. A gas check shall be made before commencement of cleaning up.

Detailed Requirements

Prior to loading, the bulkheads to the engine-room shall be inspected and approved by the Administration as gastight and the safety of the bilge pumping arrangements shall be approved by the Administration. Inadvertent pumping through machinery spaces shall be avoided.

(i) Where the bilge suction valve of the cargo space is located in the machinery space the valve shall be checked and the valve lid and seat lapped to a fine finish, as necessary. After re-assembly the valve shall be locked shut and a notice shall be placed adjacent to the valve warning against opening without the master's permission.
(ii) All pipes passing through the cargo space shall be in good order and condition. Hold atmosphere sampling units shall be effectively blanked off.
(iii) Electrical circuits for equipment in cargo spaces which is unsuitable for use in an explosive atmosphere shall be isolated by removal of links in the system other than fuses.
(iv) The cargo spaces shall be ventilated by at least two separate fans which shall be explosion-proof and arranged so that the escaping gas flow is separated from electrical cables and components. The total ventilation shall be at least 6 air changes per hour, based on an empty cargo space.
(v) Ventilator trunkings shall be in sound condition and so arranged to preclude interconnection of the atmosphere in the cargo space with other cargo spaces, accommodation or work areas.

Operational Requirements

(i) Smoking and naked flame shall be prohibited on deck in the vicinity of the cargo space or in the cargo space itself during loading or discharging.

(ii) Any portable lighting shall be safe for use in an explosive atmosphere.

(iii) The cargo shall be kept dry and during wet weather conditions cargo handling shall be suspended and the cargo space shall be closed.

(iv) Sets of self-contained breathing apparatus shall be located and stored for immediate use together with lifeline and a gas detector.

(v) Prior to commencement of discharging, the atmosphere in the cargo space shall be tested for the presence of toxic and flammable gases.

(vi) Checks for contaminant gases shall be carried out at 30-minute intervals while persons are in the cargo space.

(vii) Entry into the cargo space shall be prohibited when gas concentrations exceed the Threshold Limit Values, for phosphine (0.3 ppm) for arsine (0.05 ppm) or where the oxygen level is below 18%^footnote.

Gases Releases from Ferrosilicon Impurities when Water is Added

(i) Arsine

Arsine is a toxic, colourless gas with a garlic like odour.

Toxicity

Arsine is a nerve and blood poison. There is generally a delay before the onset of symptoms (sometimes a day or so). These are at first indefinite.

Symptoms

1 Feeling of malaise, difficulty in breathing, severe headache, giddiness, fainting fits, nausea, vomiting and gastric disturbances.

2 In severe cases, vomiting may be pronounced, the mucous membranes may have a bluish discolouration and urine is dark and bloodstained. After a day or so there is severe anaemia and jaundice.

Concentration

A concentration of 500 ppm is lethal to humans after exposure of a few minutes, while concentrations of 250 ppm are dangerous to life after 30 minutes exposure. Concentrations of 6.25 to 15.5 ppm are dangerous after exposure of 30 to 60 minutes. A concentration of 0.05 ppm is the threshold long limit to which a person may be exposed.

(ii) Phosphine

Phosphine is colourless, flammable and highly toxic and has the odour of rotting fish.

Toxicity

Phosphine acts on the central nervous system and the blood.

Symptoms

The symptoms exhibited by phosphine poisoning are an oppressed feeling in the chest, headache, vertigo, general debility, loss of appetite and great thirst. Concentrations of 2000 ppm for a few minutes and 400 to 600 ppm are dangerous to life. 0.3 ppm is the maximum concentration tolerable for several hours without symptoms. No long-term exposures to this gas shall be permitted.