Liquid Chlorine

SECTION 2: Hazards identification

MAIN HAZARDS R23: Toxic by inhalation. R36/37/38: .Extremely irritating to eyes, respiratory system and skin. S7/9: Keep container tightly closed and in a well ventilated place. S44:.If you feel unwell seek medical advice and show the label where possible. USA TLV (TWA) 0,5 ppm (1,5 mg/m3) USA TLV (STEL) 1 ppm (3 mg/m3) Germany MAK 0,5 ppm (1,5 mg/m3) Cl2

Health hazards

4 Fire Hazard: 0 Reactivity Hazard: 0 Specific hazards: OX CHEMICAL HAZARDS Chlorine may react explosively with amidosulphuric acid; antimony trichloride and tetramethylsilane (at 100°C); tert-butanol; butyl rubber and naphtha ; carbon disulphide ; 3-chloropropyne ; dibutyl phthalate ; dichloro(methyl)arsine ; disilyl oxide; glycerol ; white phosphorus (at -34°C); hexachlorodisilane ; diborane; stibine; ethylphosphene; silicones ; synthetic rubber ; aluminium ; oxygen difluoride (on warming) ;benzene); tetraselenium tetranitride; dimethyl phosphoramidate ; recovered methanol ; methanol and tetrepyridinecobalt(II) chloride ; methane (over yellow mercury oxide); ethylene; ethane; and gasoline. Explosive reactions with acetylene have occurred under a variety of conditions. Injection of liquid chlorine into a naphtha-sodium mixture caused a violent explosion; other incidents involving saturated hydrocarbons and chlorine have been reported , as have incidents involving organic auxiliary materials. Precautions to prevent explosions during chlorination of solid paraffin hydrocarbons are available . Combination of chlorine and hydrogen may be explosive over a wide range of conditions, and equimolar mixtures of chlorine and hydrogen containing 0,1-0,2% nitrogen trichloride explode in the absence of light if the pressure is below a limiting value. Explosibility of chlorine and hydrogen with air, hydrogen chloride, oxygen or inert gases has been discussed. Ammonia-chlorine mixtures may be explosive, and explosions have occurred with other nitrogen compounds such as impure biuret; or nitrogen triiodide. The dangerously explosive nitrogen chloride may be formed on reaction of chlorine with amidosulphuric acid; acidic ammonium chloride solutions; alkylthiouronium salts; 2,4,6-triketo-hexahydro-1,3,5-triazine (cyanuric acid). Explosions have also been reported with tetramethyl thionophosphate; during preparation of chloronitromethane by adding portions of dry sodium aci-nitromethanide to chlorine; during preparation of iron(II) chloride from iron powder and chlorine gas in a chlorinated pyridine solvent ; during preparation of cis-dichlorobis (2,2'- bipyridyl)cobalt(III) chloride by passing chlorine into an ice-cold solution of cobalt chloride, bipyridyl and lithium chloride in methanol. A violent explosion occurred in PVC drying towers in a mercury amalgam cell chlorine plant following failure of the pumped mercury circulation. This caused liberation of hydrogen at the cathodes and oxygen at the anodes, so chlorine gas output fed into the drying towers trickle-fed with concentrated sulphuric acid contained hydrogen and oxygen. The explosive mixture was ignited by static sparks . Excess hydrogen chloride is used during oxycholination of ethylene to 1,2-dichloroethane to keep the reaction mixture outside explosive limits. The fire and explosion hazards of chlorine-containing systems have been reviewed. Chlorine may form explosive products with sodium chloride; phenylmagnesium bromide ; aziridine ; 2- chloroalkyl aryl sulphides in the presence of lithium perchlorate ; and bis (2,4-dinitrophenyl) disulphide. The product form chlorination of 4,4'-dithiodimorpholine exploded violently. Dioxygen difluoride may ignite or explode with chlorine in the range of -130°C to -190°C. Chlorine and fluorine mixtures (containing essential moisture) ignite on sparking and then explode; heating fluorine and chlorine in a Monel pressure vessel gives contained explosions at around 100°C. The following may ignite on contact with chlorine: methane and oxygen; hydrazine; hydroxylamine; calcium nitride; diethyl ether; diethylzinc; potassium, sodium and copper hydrides; boron; active carbon; silicon; phosphorus; arsenic powder; arsine; phosphine; silane; trialkyl boranes (lower homologues); dicopper acetylide; zirconium dicarbide (at 250°C; arsenic disulphide; boron trisulphide; mercuric sulphide; borondiiodophosphide; phosphrous trioxide; trimercury tetraphosphide. Trimagnesium diphosphide and trimanganese diphosphide ignite in warm chlorine. Metals such as tin, aluminium, brass, calcium, copper, iron, manganese, potassium, antimony, bismuth, magnesium, sodium, zinc, thorium, tin, uranium, nickel, mercury, aluminium-titanium alloys and niobium ignite in chlorine under various conditions. Titanium is not suitable for components in contact with dry chlorine gas or liquid. Steel ignites in chlorine under various conditions. Ignition has occurred during continuous chlorination of polyisobutene. Presence of chlorine lowers the auto-ignition temperatures of various halogenated hydrocarbons such as chloromethane, dichloromethane and 1,2-dichloropropane. Gaseous mixtures of chloromethane and chlorine are detonable in the range 12.5-55%, and liquid mixtures of dichloromethane and chlorine may also be detonable. Cl2 Saturated solutions of chlorine in DMF are hazardous and will self-heat and erupt under adiabatic or non-adiabatic conditions. Addition of Lewis acid catalyst to a chlorine-hydrocarbon mixture is very hazardous. Various monomers decompose violently when treated with chlorine in the presence of steel or iron (III) chloride. Polychlorobiphenyl process oil and liquid chlorine react exothermically between 25 and 81°C confined in a stainless steel bomb. Reaction with dinitroanilines is vigorous. Iron carbide; strontium acetylide; uranium dicarbide; boron phosphide; tungsten dioxide (on warming); caesium oxide (above 150-200°C); arsenic (at -34°C); and tellurium (on warming) incandesce in chlorine. Lithium acetylide and monolithium acetylide burn brilliantly in chlorine; caesium acetylide and monocaesium acetylide also burn in chlorine at or near ambient temperature. Powdered copper phosphide burns vigorously in chlorine. Contact with bromine pentafluoride at ambient or slightly elevated temperatures is violent, ignition often occurring. Chlorine may react violently with N-arylsulphamides (63); or sodium hydroxide. BIOLOGICAL HAZARDS Chlorine is extremely irritating to the skin, eyes and respiratory tract. It may cause corrosion of the teeth. Prolonged exposure to low concentrations may cause chloracne. Several reviews of chlorine toxicity and toxicology are available.

Potential health effects

INHALATION The gas causes severe lung irritation and damage. High concentrations are asphyxiant by causing muscular spasms of the larynx (choking), swelling of the mucous membranes, nausea, vomiting, anxiety, syncope, and may be fatal. Acute respiratory distress including cough, bloody spit, chest pain, dyspnoea, and cyanosis may develop, and tracheobronchitis, pulmonary oedema and pneumonia may supervene later. In human volunteers the threshold of odour perception is 0,2-0,4 ppm with considerable variation, and 0,006 ppm when the odour of chlorine is first detected. Odour detection is not a good warning device for chlorine hardened workers. 0,2 ppm for 4-20 minutes causes itching of the nose; 1 ppm sore eyes, dry throat, coughing and a feeling of difficulty inhaling; 1,3 ppm caused some subjects severe shortness of breath and violent headache after 30 minutes; throat irritation at 15 ppm, cough at 30 ppm and 1000 ppm is fatal after a few deep breaths. The TCLO in humans producing respiratory distress is reported as 15 ppm and the LCLO 430 ppm for a 30 minute exposure. Although concentrations up to 15 ppm reportedly caused a case of chronic poisoning after several years exposure and decreased lung capacity in workers 3 years after moderately severe acute exposure, there is not enough well documented evidence to conclude there is a chronic impairment of lung function after acute or chronic exposure to chlorine. It may, however, aggravate pre-existing conditions like tuberculosis or heart disease. A "possibly significant difference" in abnormal electrocardiograms is reported in chlor-alkali plants. No serious neoplasia or serious acute pulmonary disease was reported. - EYES Chlorine gas is a severe irritant of the eyes. Symptoms include stinging and burning sensation and tear formation. The gas can cause conjunctivitis. Direct contact with liquid chlorine may cause burns, permanent damage and possible blindness. Eye irritation reportedly occurs at 7-8 ppm . - INGESTION Cl2 Ingestion is not an applicable route of exposure for gases. CARCINOGENICITY No information is available concerning the carcinogenicity of chlorine. MUTAGENICITY Addition of chlorine to human lymphocytes in vitro at concentrations above 20 ppm caused increased chromosome breaks, gaps, translocations and dicentrics, but no effects were observed at concentrations below this. REPRODUCTIVE HAZARDS No evidence of foetotoxicity or teratogenicity.

Health Effects - Skin

In high concentrations the gas causes skin irritation with a burning and pricking feeling, swelling and vesicle formation. The liquid causes burns on contact; short exposure leads to first degree burns, while long exposure leads to second degree burns.