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Guidance For Transporting Ammonia By Rail

*2007 SECOND EDITION*
*(First Edition 2005)*

Copyright 2007 EFMA

EFMA European Fertilizer Manufacturers Association

Avenue E. van Nieuwenhuyse 4 B-1160 Brussels Belgium


CONTENTS

  1. INTRODUCTION 6
  2. PROPERTIES AND CLASSIFICATION OF AMMONIA 6
  3. DESIGN AND CONSTRUCTION OF RAILWAY TANK CARS (RTCS) 13
  4. DANGEROUS GOODS MARKING AND LABELLING 23
  5. RECOMMENDATIONS FOR CONTRACTING AND MAINTENANCE OF RTCS 28
  6. PERSONAL PROTECTIVE CLOTHING AND SAFETY EQUIPMENT 30
  7. LOADING AND UNLOADING OPERATIONS 31
  8. TRANSPORTATION 43
  9. AUDITS 47
  10. EMERGENCY RESPONSE 48
  11. QUESTIONS AND ANSWERS 53
  12. REFERENCES 56

ANNEX 1: Ammonia Rail Transport Accident Analyses

ANNEX 2: Abbreviations

ANNEX 3: Nomograph to show some properties of Ammonia

ANNEX 4: Methods used to mitigate the consequences of a loss of containment

ANNEX 5: Example of a checklist

ANNEX 6: Glossary of terms used

ANNEX 7: Special checking requirements before and after the filling of class 2 products (e.g. ammonia) referred to in RID 4.3.3.4.


Disclaimer

This publication has been prepared by the member companies of the European Fertilizer Manufacturers Association (EFMA). Neither the Association, any individual member company nor any individual representative of the member company can accept liability for accident or loss attributable to use of the information given in this Booklet. Users of this Booklet are advised to consult the latest national and international regulations as these may have changed since its publication.


1. INTRODUCTION

This Guidance for the transport and handling of ammonia has been drawn up by the European Fertilizer Manufacturers Association (EFMA), with the help and expertise of members in order to ensure high safety standards in operations involving ammonia transport. The Guidance deals exclusively with the transport of anhydrous ammonia in rail tank cars (RTC). The importance of ammonia rail transport for the European fertilizer and chemical producers is considerable. Every year more than 1,500,000 tonnes of ammonia are transported in Western Europe by rail. Ammonia is toxic and therefore a number of safety precautions are taken to ensure that the relevant operations are carried out safely. EFMA has analysed ammonia rail transport accidents in Europe to get a clear understanding of their causes and consequences. This analysis showed that none of the accidents, injuries or casualties was due to the release of ammonia (see Annex 1). The purpose of this Guidance is to improve further the safe handling and transport of anhydrous ammonia throughout the European Union as part of EFMA’s Product Stewardship programme [Ref. 12]. The transport of ammonia is subject to stringent national and international regulations [Ref. 1-4]. The recommendations made in this Guidance go beyond the requirements of these rules and it is recommended that all those involved in the handling and transport of ammonia adopt them as appropriate. Every user of this Guidance is advised to give due consideration to the specific circumstances of their installation and situation when applying this Guidance. No part of the Guidance should be applied or interpreted in such a way that conflicts with existing national and/or international regulations. In all cases, such legal requirements must always take precedence over any part of the Guidance. This 2007 booklet is an updated version of the 2005 booklet. The updated text mainly relates to a revision of the RID [Ref 2].


2. PROPERTIES AND CLASSIFICATION OF AMMONIA

2.1 General Characteristics

  • Chemical formula: NH3
  • Chemical name: Ammonia, Anhydrous Ammonia
  • UN Number: 1005
  • CAS Number: 7664-41-7
  • Molecular weight: 17.03

At ambient temperature and atmospheric pressure, ammonia is an alkaline, colourless gas with a pungent and suffocating odour. Ammonia gas is very soluble in water. The gas is strongly irritant/corrosive to the skin, eyes and respiratory tract and has toxic properties. Ammonia gas condenses into a colourless liquid when cooled and compressed. The liquid can cause severe cold burns on contact with the skin.

2.2 Physical Properties of Ammonia

Table 1 [Ref 5.] summarises a number of common physical data.


PropertyLiquidGas
ColourColourlessColourless
SmellPungentPungent
Density (0°C, 101.3 kPa)638.6 kg/m30.7714 kg/m3
Density (-33.43°C, 101.3 kPa)682 kg/m30.888 kg/m3
Boiling point (101.3 kPa)-33.43°C-
Melting point-77.71°C-
Critical temperature132.4°C-
Critical pressure11.28 MPa-
Critical viscosity23.90 x 10^-3 mPa.s-
Specific Heat (10°C, 1 MPa)4.67 x kJ/kg K-
Specific Heat (-33.4°C, 1MPa)4.47 x kJ/kg K-
Heat of Vaporisation (101.3 kPa)1370 kJ/kg-
Heat of Solution (1:1 mol H2O, 0°C)30.69 kJ/mol NH3-

Table 2 gives the effect of temperature on the solubility of ammonia in water [Ref. 13].


Temperature °CSolubility in water, wt% NH3
1040.0
2034.2
3028.5
4023.7
5018.5

Table 3 summarises the change in density of liquid ammonia with temperature. [Ref.13]


Temperature °CDensity of Liquid Ammonia, kg/m3
-33682
-15659
0639
10625
20610
30595
40580
50563
60545
70540

2.3 Chemical Properties of Ammonia

Ammonia is an alkaline gas. The pH of a 1% aqueous solution is approximately 11.7. Ammonia in contact with certain other chemicals including mercury, chlorine, iodine, bromine, calcium, silver oxide or hypochlorites can form explosive compounds. Gaseous ammonia can react violently with nitrogen oxides and strong acids. Ammonia is very corrosive to copper and copper containing alloys and therefore, equipment in contact with ammonia must be free of them.

2.4 Health Hazards of Ammonia

Ammonia is a potentially hazardous substance, although it occurs naturally as a result of many biological processes. It can produce acute effects on humans and animals. It has strong alkaline and hygroscopic properties, which cause a primary irritation or corrosion to damp tissue surfaces, such as the eyes, respiratory system and skin. Ammonia has a pungent odour; the odour threshold of ammonia is in the region of 5 ppm. Concentrations between 20-50 ppm in air are detectable by most people. This provides an adequate warning of its presence well below the hazardous concentration levels. Gaseous ammonia affects the mucous membranes and the respiratory tract and severely irritates the eyes. Inhaling high concentrations may cause pulmonary oedema. High gas concentrations in the air may also cause blisters and chemical burns to the skin. The effects of exposure to various vapour concentrations are summarised in Table 4 [Ref. 14].


Vapour Concentration (ppm v/v)General effectExposure period
5Odour detectable by some people.-
25-Occupational exposure standard - 8hr/TWA
35-Occupational exposure standard – short term, 15 mins
50-100Irritation detectable by most peopleTolerable up to 2 hours.
400-700Immediate eye, nose, and throat irritation.1/2-1 hr exposure causes no serious damage
1000-2000Severe coughing, severe eye, nose, and throat irritation.Damage to eyes and respiratory system quick
3000-4000Severe coughing, severe eye, nose, and throat irritation.Could be fatal after 30 mins
5000-12000Respiratory spasm, rapid asphyxia.Fatal within minutes

Liquid ammonia in direct contact with the skin freezes tissues on contact and causes chemical burns.

Threshold Limit Values.

The EU threshold values are:

  • TLV/15 min TWA: 50 ppm = 36 mg/m3
  • TLV/8 hr TWA: 20 ppm = 14 mg/m3

Note: Threshold Limit Values and terminology differ in different countries.

2.5 Fire Hazard

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