MSC 85/26/Add.2 ANNEX 3 RESOLUTION MSC.268(85) - US Coast ...

MSC 85/26/Add.2ANNEX 3Page 178(vi) Checks for contaminant gases shall be carried out at 30-minute intervals while personsare in the cargo space.(vii) Entry into the cargo space shall be prohibited when gas concentrations exceed theThreshold Limit Values, for phosphine (0.3 ppm) for arsine (0.05 ppm) or where theoxygen level is below 18%.GASES RELEASES FROM FERROSILICON IMPURITIES WHEN WATER IS ADDED(i)ArsineArsine is a toxic, colourless gas with a garlic like odour.ToxicityArsine 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.Symptoms1 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 bluishdiscolouration and urine is dark and bloodstained. After a day or so there is severe anaemia andjaundice.ConcentrationA concentration of 500 ppm is lethal to humans after exposure of a few minutes, whileconcentrations of 250 ppm are dangerous to life after 30 minutes exposure. Concentrationsof 6.25 to 15.5 ppm are dangerous after exposure of 30 to 60 minutes. A concentrationof 0.05 ppm is the threshold long limit to which a person may be exposed.(ii)PhosphinePhosphine is colourless, flammable and highly toxic and has the odour of rotting fish.ToxicityPhosphine acts on the central nervous system and the blood.SymptomsThe 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 fewminutes and 400 to 600 ppm are dangerous to life. 0.3 ppm is the maximum concentrationtolerable for several hours without symptoms.No long-term exposures to this gas shall be permitted.I:\MSC\85\26-Add-2.doc