Intergovernmental Organization for the Development of Refrigeration
International Institute of Refrigeration
177 Bd Malesherbes – 75017 PARIS, France
23rd Informatory Note on Refrigeration Technologies
Several cases of explosions occurring in marine refrigerated containers (reefers) have been reported in various parts of the world in recent months. Besides causing major material damage, these accidents have resulted in the deaths of several operators. The assessments performed following these accidents have established that these explosions were due to the use, for maintenance of refrigeration equipment, of counterfeit refrigerants containing R40 mixed with R134a, the refrigerant initially used in these units. A report published by the Container Owners Association1 describes the global situation concerning contamination of R134a by a refrigerant mixture composed primarily of R22, R30, R40 and R142b. There are no external signs indicating that counterfeit refrigerants have been used during maintenance operations.
Over 1.3 million reefers are in use worldwide,2 and counterfeit refrigerants represent a potential risk for all operators servicing this equipment or handling it in ports, on ships, during land transport and loading and unloading at hubs, or in warehouses or factories. It is estimated that around 5000 containers have been tested for contamination so far and around 10-15% of the world fleet may be contaminated. 3
Moreover, similar cases involving automobile or bus air-conditioning systems have been reported in the Far East, the Middle East and Greece.4 Replacement refrigerants with unknown composition are known to be available on the black market. In particular, cases of contamination with hydrocarbon refrigerants have been reported.
The goals of this Note are to raise the awareness of operators concerning this new risk, to propose a detection method designed to detect systems containing counterfeit refrigerants that thus constitute a risk, and to examine ways of decontaminating contaminated systems. The aim is also to attract the attention of public authorities and decision-makers regarding the impact of counterfeit refrigerants on the refrigeration sector, with respect to safety and also in economic terms.
The current situation and risks associated with R40
• Reasons underlying the use of counterfeit products and the consequences of such use: the addition of other refrigerants to R134a in order to intentionally make the mixtures obtained resemble pure R134a markedly reduces the cost of the counterfeit product with respect to that of R134a, and an opportunity for financial gain for counterfeiters. The counterfeit market is encouraged by the recent price spikes in the worldwide cost of R134a as a result of the phase-out of HCFCs, and this is stimulating the market for counterfeit R134a. This results in safety issues for operators of course, and also gives rise to costs for the refrigeration industry: certain refrigeration stakeholders consider that counterfeit refrigerants cost several million US dollars per year.5
• Known causes of accidents: several containers have exploded in Vietnam, South America, North America and Asia. Analyses of material have demonstrated that these explosions resulted from the presence of trimethyl aluminium (Al2(CH3)6), which is liquid at room temperature. This substance is produced by the reaction of the refrigerant used to replace R134a, i.e. methyl chloride (chloromethane or CH3Cl), R40, when it enters into contact with the aluminium contained in the compressor or the refrigeration circuit.
• Risks: it is likely that other systems that have undergone maintenance operations during which counterfeit refrigerants have been used are circulating in various parts of the world, including Europe. On contact with aluminium in the equipment, these refrigerants gradually react, and can cause an explosion at any time during use, or during maintenance operations, and can even cause fires. The use of steel piping is the best way of preventing such risks.
Methyl chloride, also known as chloromethane (CH3Cl) or R40, was used as a refrigerant prior to the advent of chlorofluorocarbons (CFCs). Because of its impact on ozone-depleting mechanisms, it is no longer used as a refrigerant. It is colourless, and has a mild ethereal odour which is not transmitted to foodstuffs accidentally exposed to it in vapour form. At temperatures below 100°C, it is not corrosive with respect to metals commonly used in the refrigeration sector, but it reacts with zinc, aluminium and light alloys.
• Risks associated with R40: R40 is flammable under certain conditions; a mixture of methyl chloride vapour and air can explode when the concentration reaches 9-15% in the presence of a source of heat.
If a major leak of this refrigerant occurs, care must be taken to ventilate before detecting the leak using a halide lamp.
The reaction of R40 with aluminium also forms highly flammable gases which become self-igniting and explosive when in contact with air. Aluminium is gradually dissolved by R40. Lubricating oil does not prevent this dangerous reaction. R40 also reacts with the aluminium compressors used in mobile refrigeration systems, and plastic components can also react on exposure to R40. The refrigerant lines can also be seriously damaged by R40.
POE oil used to lubricate refrigeration system is highly saponified on reaction with R40, and its initial components separate out. These reactions form acids and alcohols.
Prevention of risks associated with R40
All operators must be informed regarding risks and must implement measures designed to prevent risks.
• How to detect counterfeit refrigerants: R40 is readily detected by using a halide lamp that does not detect R134a. Counterfeit refrigerants can be mixed with R40, R22 or R142b, but these components can also be detected by using a halide lamp. Such detection must be performed in a well-ventilated area.
In order to test a cylinder or a system, it is unfortunately necessary to trigger a small refrigerant leak then to analyse the gas using a halide lamp. The system must be stopped in order to perform this operation safely. No marine-shipping-container refrigerant test procedures have been developed to date.
New models of refrigerant analyzers for use with R134a systems are announced to detect R40 in concentrations as low as 2%.5
• Isolate and clean systems containing counterfeit refrigerants: in order to prevent risks, at-risk systems must be isolated, stopped then decontaminated if possible. For operators involved only in the transport, loading or unloading of containers, it is advisable to ask the operator to specify whether or not the system has been checked and provided with a compliance certificate indicating that no counterfeit refrigerants are present.
• Avoid the use of counterfeit refrigerants: in order to prevent risks, it is above all essential to avoid the use of counterfeit refrigerants by monitoring maintenance operators and their refrigerant supplies. Maintenance of the systems concerned by explosions had been conducted in Asia. Compliance certificates may be needed for cylinders: methyl chloride can be detected in cylinders.
How to decontaminate systems contamined with R40
Several methods have been proposed in order to decontaminate systems, but to date none of them have been validated or widely used.
Methyl chloride can be recovered in the gaseous form; however, the trimethyl aluminium formed when methyl chloride reacts with aluminium is liquid at room temperature. Trimethyl aluminium accumulates at the lowest point in the refrigerant circuit, in particular in the compressor housing, where it can be recovered.
There is a significant risk associated with the use of counterfeit refrgerants containing R40 in marine containers. Operators need to be made aware of such risks, and must implement preventive measures and set up:
• a certification scheme governing the refrigerants used in maintenance,
• certification of marine containers for logistics interfaces,
• a method of decontaminating contaminated systems.
Beyond the use in marine containers, vigilance must be strengthened with respect to other applications and refrigerants used in these domains, in particular automobile and bus air conditioning and on-board refrigeration.
Finally, another important aspect: at the level of public authorities, control measures and deterrence need to be strengthened in order to prevent the use of counterfeit refrigerants.
This Informatory Note was prepared by Gérald Cavalier, (Executive Director of Cemafroid, Head of the IIR’s Section D, Storage and transport) and Richard Lawton (Technical Director, Cambridge Refrigeration Technology, President of the IIR’s Commission D2, Refrigerated transport). It was reviewed by several of the IIR’s international experts.
1. Report of the 3rd COA Reefer Forum on Counterfeit Refrigerants/Contaminated Machinery, Singapore, February 2012, 9th.
2. Industry Action Report, Container Owners Association, January 2012. www.containerownersassociation.org
6. 4. http://www2.dupont.com/Refrigerants/en_US/brand_assurance/index.html.
7. Fiche de sécurité du R40, R22, R134a. www.cemafroid.fr/doc_telechargement/Note%20fluides%20frelates%20V4.pdf
8. UNEP. Report of the Refrigeration, Air conditioning and Heat Pumps Technical Options Committee, 2010.
9. Audits de certification des opérateurs manipulant des fluides frigorigènes par le Cemafroid.
10. Revised Information Regarding Counterfeit Refrigerants, Cambridge Refrigeration Technology, November 24, 2011
11. Formulaire du froid. Martel R, Rapin P. Xe édition.