Requirements for means of transport in the cold chain

The cold chain is a key element in many sectors of the economy, such as the food, catering, chemical, pharmaceutical and medical industries. It is a comprehensive system ensuring the appropriate temperature for a given product group at the stages of production, logistics and sales. Maintaining appropriate parameters, most often reduced temperature, slows degradation processes, extends storage life and ensures product quality. There are numerous standards, guidelines and legal acts that define requirements for equipment, temperature and cold-chain management. The properties of products designated as highly perishable, such as vegetables, fruit, fresh and frozen meat and fish and other foodstuffs, as well as cut flowers and plants, pharmaceutical products, etc., undergo degradation over time because they naturally undergo certain chemical and physical processes. The rate of these reactions can be limited by storing and transporting them in temperature-controlled environments. To prevent goods damage caused by unsuitable temperature conditions favouring growth of pathogenic microorganisms or toxin formation, food, pharmaceutical and medical companies increasingly rely on the cold chain. The concept of the cold chain refers to activities aimed at ensuring the appropriate temperature of raw materials, ingredients, intermediate products or finished temperature-sensitive products from manufacture to consumption, and includes elements such as product cooling/freezing, storage and transport. Food losses and waste have become a serious problem affecting energy needs, environmental degradation and climate change. Causes of food losses and waste in supply chains are complex and occur throughout their range, from production to consumption. This problem has also been recognised in our country, and the Act of 19 July 2019 on counteracting food waste in force in Poland “defines rules for handling food and obligations of food sellers in order to counteract food waste and the negative social, environmental and economic effects resulting from food waste”, and corresponding implementing acts impose certain obligations on large-format retail outlets selling food. The phenomenon of food waste of course also concerns processing, catering, production and households, where it is largely linked to consumer awareness. For goods subject to cold-chain requirements such as medicines, pharmaceuticals and vaccines, maintaining strictly defined conditions with appropriate temperature at all stages aims to eliminate situations in which they could become dangerous to health. It is also worth stressing that companies transporting this type of cargo often describe it as “valuable/costly cargo” or “carriage of expensive goods”; declared cargo value may range from several hundred to even several million euro.

ACTIONS AGAINST FOOD WASTE

Climate change and food waste are closely linked; according to the latest data, 8% of greenhouse gas emissions is accounted for by food waste. In connection with this the Food and Agriculture Organization of the United Nations (FAO) and the United Nations Environment Programme (UNEP) established the International Day of Awareness of Food Loss and Waste (IDAFLW), which falls on 29 September. According to FAO about 33% of all food intended for consumption produced in the world is wasted or lost. Reducing food losses and waste is also an integral part of the EU “farm to fork” strategy for a fair, healthy and environmentally friendly food system. To accelerate EU progress toward this goal, the EU Commission proposed that by 2030 Member States reduce food waste by 10% in processing and production and by 30% (per capita) combined in retail and consumption (restaurants, catering services and households).

TRANSPORT AS ONE OF THE BASIC LINKS OF THE COLD CHAIN

Transport of temperature-sensitive products may take place by land (road and rail), sea and air. Sensitive goods require a special type of equipment and are subject to a number of restrictions, and choice of carriage mode depends on the transport and handling susceptibility of these articles. In general, the minimum requirements for means of transport, regardless of type, are:

• ability to maintain the required temperature inside the cargo space; • high thermal insulation class (low overall heat transfer coefficient K); • ability to protect the cargo against harmful weather effects; tightness; cleanliness; • good technical condition.

ROAD TRANSPORT

Road transport of temperature-sensitive products uses trucks, trailers, semi-trailers and containers equipped with refrigeration units, heating units or refrigeration-heating units, as well as insulated tanks used for liquid products. To unify standards for transport of highly perishable foodstuffs the Agreement on the International Carriage of Perishable Foodstuffs and on the Special Equipment to be Used for such Carriage (the so-called ATP Agreement) was created. The ATP Agreement requires that international food transport use a specified type of equipment and that it be regularly tested and checked. The ATP Agreement covers road, rail and in special cases sea transport over a distance of less than 150 km. ATP also defines classification, marking of special vehicles and temperatures required during carriage for individual groups of food products [2, 3]. Classification is based on insulation quality and performance of the thermal unit, i.e. refrigeration, heating or refrigeration-heating unit. Both the isothermal body and the unit (if installed) should comply with the ATP Agreement, which defines the test methodology for these elements and conditions for recognising serially produced means of transport with a tested prototype, the so-called prototype means of transport, as well as the method of selecting refrigeration/heating units. The overall heat transfer coefficient allowing qualification as ATP-compliant should not exceed specified values. Checks and conformity confirmation are performed by authorised ATP stations, the list of which is published on the UNECE website. The Agreement is regularly updated. It provides for two insulation classes:

• IN means of transport with normal insulation – characterised by a K coefficient equal to or less than 0.70 W/(m²·K);

• IR means of transport with reinforced insulation – K coefficient equal to or less than 0.40 W/(m²·K) and walls at least 45 mm thick for means of transport wider than 2.50 m.

For multi-compartment road means of transport (so-called multi-temperature):

• if it is a vehicle divided into two compartments, the marking of the means of transport should consist of the identification marks for each compartment (example: FRC-FRA), starting from the compartment at the front or left side of the means of transport;

• for others, only the identification mark for the highest ATP class should be chosen, i.e. the class allowing the greatest difference between internal and external temperature, and supplemented with the letter M (example: FRC-M).

If the means of transport is equipped with a removable or dependent thermal unit and if there are special conditions of use, the identification mark or marks should be supplemented with the letter X in the cases provided for in the ATP Agreement (example: FRCX). Means of transport equipped with thermal units must have one of the insulation classes listed above and are divided into:

• iceboxes – sources of cold other than mechanical or absorption units (natural ice with or without salt, eutectic plates, dry ice with or without a device allowing sublimation control, liquefied gases with or without an evaporation control device, etc.);

• mechanically refrigerated means of transport – equipped with an individual refrigeration unit or one common to several means of transport (mechanical compressor unit, absorption unit, etc.);

• heated means of transport – equipped with a heating unit; means of transport with a mechanical refrigeration-heating unit – equipped with an individual refrigeration unit or one common to several means of transport (mechanical compressor unit, absorption unit, etc.) and a heating unit (electric heater, etc.) or a refrigeration-heating unit [2, 3].

RAIL TRANSPORT

In rail transport of sensitive cargo, refrigerated containers with self-contained refrigeration units adapted to maintain temperature are currently used primarily, and for more demanding cargo – containers equipped with devices enabling control of atmosphere composition, temperature and humidity. Advantages of this type of transport include lower exposure of the cargo to mechanical damage, because changes of direction, acceleration and braking are not as sudden as in road transport, as well as environmental aspects. Use of rail transport for carriage of goods under controlled temperature conditions in Poland is not very large, the reason being low average speed of freight trains resulting in longer transport time. Rail carriage time is currently much shorter than sea, but on average twice as long as road and many times longer than air. Requirements for rail means of transport carrying food and the method of their classification, as for road means of transport, are contained in the above-mentioned ATP Agreement.

SEA TRANSPORT

Sea transport is considered the cheapest form of carriage, especially over longer distances; it allows very large loads to be carried at once, but is time-consuming. Food is transported primarily in containers; the most popular are 20 ft and 40 ft refrigerated containers. Goods delivered to ports are then distributed by rail or road transport. Overall external dimensions and tolerances of thermal containers should comply with ISO 668; because of the specificity of this type of transport no part of the container may protrude beyond the specified overall external dimensions.

AIR TRANSPORT

Air logistics is the fastest and at the same time the most expensive of the listed modes of transport. Products less sensitive to temperature may be sent on line aircraft, in cargo holds where a temperature of 15°C is maintained. When a lower carriage temperature is required, refrigerated containers with temperature control capability are necessary. As with sea containers and those used for road transport, standardisation has also been introduced in air transport. Standards and regulations for air transport of temperature-controlled goods are under the supervision of the International Air Transport Association (IATA). In addition to IATA rules there are also specific requirements that must be met at carrier level and under regulations in a given country. Dimensions of air containers compliant with IATA requirements must be adapted to the aircraft fuselage and are designated as ULD (Unit Load Devices); different dimensions allow appropriate use of space and facilitate loading and unloading. Air transport, characterised by lower exposure of cargo to damage, allows packaging of special composites or aluminium and of significantly lower mass. Limitations in air transport are cargo dimensions and weight and the height of the aircraft cargo hold. The source of cold in temperature-controlled containers may be “dry ice” or a typical vapour-compression refrigeration system. These containers are also equipped with heating systems and air circulation systems.

INTERMODAL TRANSPORT

The requirement to optimise costs and the need to shorten transport time require advanced transport technologies. One such solution is intermodal transport. It consists in combining rail and road carriage without the need to reload goods, which improves carriage, lowers transport costs, shortens its time and relieves excessively congested roads. Two techniques are mainly used: carriage of trucks or combinations on wagons and carriage of semi-trailers on wagons. In the first case transport takes place on specialist low-floor platform-type wagons, because of the need to maintain the legally permitted cargo height. For semi-trailers, platforms or pocket wagons are used. For refrigerated swap bodies a technique is also used consisting in detaching them from chassis and carrying them on rail wagons, as with containers. These bodies, like containers, are subject to standardisation. An advantage of this system is the ability to load and unload quickly without the need for special terminal investments. Similar forms of intermodal transport are used consisting in combining road with sea and rail with sea transport.

TESTING AND CERTIFICATION

Testing of means of transport carrying temperature-sensitive goods is performed depending on the type of transport for which they are used. The ATP Agreement covers road and rail means of transport, and the so-called ATP certificate is a document required when performing international carriage. Requirements and test methodology for insulated means of transport for temperature-sensitive goods are also discussed in PN-EN 17066-1:2019. It covers all thermally insulated means of transport (trucks, trailers, tanks, vans, wagons, land transport containers, small containers, packaging), whereas no special requirements are defined for sea containers covered by ISO 1496-2. Testing of sea containers may be performed according to PN-ISO 1496-2:2020-10; this document defines basic requirements and test methods for isothermal containers. The Regulation of the Minister of Transport, Construction and Maritime Economy of 12 April 2013 on inspections, tests and recognition of containers defines, among other things, requirements for these means of transport and types and frequency of their inspections. For isothermal containers, in addition to standard requirements when submitting an application for recognition of a designed construction type, additional technical documentation must be attached, including a technical description, diagrams, drawings and thermal characteristics of the refrigeration/heating unit, electrical equipment specification, power source, thermal insulation specification, technical-thermal calculations, programme and methodology of technical-thermal tests with values that should be achieved. The scope of periodic and continuous inspections includes, beyond activities provided for other containers, additionally checking the condition of thermal insulation and air ducts affecting strength and tightness if there is suspicion of reduced insulation properties or loss of strength. Requirements for testing containers used for air transport can be found in ISO 8058 (Air cargo – Insulated container – Thermal efficiency requirements) and concern thermal performance ensuring that perishable cargoes are maintained in insulated standard containers for air transport in the best possible condition during the ground handling and air transport cycle for a maximum of 36 hours. In this standard the term “perishable cargo” refers for example to dairy products, fruit, vegetables, flowers, frozen food, meat, fish, etc., requiring maintenance of specified temperature ranges during door-to-door air transport. As mentioned earlier, guidelines for air transport are also developed by IATA.

TRANSPORT OF PHARMACEUTICALS

Special requirements for means of transport concern carriage of pharmaceutical products, which must rely on high-quality cold-chain logistics. Pharmaceutical products requiring temperature-controlled transport must be stored within the appropriate temperature range to preserve the efficacy of their active ingredients. Loss of this efficacy means wasting expensive products or delivering ineffective or harmful pharmaceuticals to people. Medicine carriage temperatures depend on storage conditions defined in temperature control rules resulting from product stability tests; the most popular carriage ranges are 2÷8°C and 15÷25°C. Medicine transport is a costly but life-saving undertaking. The document recommended when performing air transport of medicines and pharmaceuticals is the so-called CEIV Pharma certificate issued by IATA. According to information provided by this institution, the main goal of the CEIV Pharma programme is to build a network of certified pharmaceutical trade routes that meet consistent standards and ensure product integrity. CEIV certificates are also issued for perishable products. The Regulation of the Minister of Health of 13 March 2015 on the requirements of Good Distribution Practice also defines requirements with regard to transport of sensitive medicinal products and, in order to ensure maintenance of proper transport conditions between manufacturer, entrepreneur and recipient, imposes an obligation to use special equipment (e.g. thermal packaging, containers and temperature-controlled vehicles), and in temperature-controlled vehicles temperature mapping should be performed under representative conditions. Temperature monitoring equipment used during transport should be regularly maintained and calibrated. Good Distribution Practice (GDP) defines requirements and standards necessary to ensure a correct supply chain for pharmaceutical and sensitive products. These guidelines can be met by a supplier or manufacturer that has and applies appropriate technical and organisational conditions under which it is possible to use a means of transport, chamber, container or additional equipment component with properties and parameters compliant with accepted requirements confirmed by appropriate tests [10, 11]. A benefit of covering a product with GDP (GDP Pharma) certification is, among other things, confirmation of high quality of services provided in carriage and storage of products taking into account, for example, European Medicines Agency guidelines or European Union rules. This concerns appropriate transport conditions enabling maintenance of a specified temperature inside the cargo compartment or container, as well as proper securing and no possibility of contamination of carried and stored cargoes. In addition to meeting technical requirements, Good Distribution Practice covers procedures related to maintenance and management of transport and storage equipment, as well as the quality system implemented in the enterprise. A GDP certificate is increasingly a required document at the stage of selecting a supplier of medicines and other sensitive products. In many cases this document becomes necessary when performing international medicine transport.

Temperature distribution testing – mapping

Tests for means of transport may be performed based on PKN-DIN SPEC 91323:2019-08 or another document ensuring equivalent product assessment. The document classifies vehicles (means of transport) into 2 categories: A – vans (delivery vehicles), B – trucks, semi-trailers or trailers. The test procedure consists of the following stages: • heating or cooling mode – constituting the preparatory phase for tests. The means of transport with open doors is exposed to ambient temperature. After temperature equalisation and closing of the cargo compartment doors, the heating or refrigeration unit is started. The phase ends when the readings of all temperature sensors are within the set range; • steady state – recording of temperature values in a specified measuring range. Under winter conditions the minimum measurement duration is at least 2 hours, and under summer conditions 4 hours (in selected temperature ranges a unit defrost process should also be provided for); simulation of disturbances and failures (e.g. door opening, unit failure) – consisting in switching off the refrigeration/heating unit, opening the rear doors for 5 minutes and closing them again; another trial involves switching off the refrigeration/heating unit and air circulation while leaving the doors closed. Depending on the category of means of transport and cargo space dimensions, from 12 to 20 temperature sensors may be placed inside the compartment. An example sensor layout is shown in Figure 8. Outside the vehicle (cargo compartment) 4 sensors recording temperature should be located. For vans, an additional sensor should be installed in the driver’s cab. Example results of body mapping tests for steady state in the temperature range (2÷8°C) are contained in Figure 10.

MANAGEMENT SYSTEMS

Rules and regulations limit the risk of product damage and loss while ensuring safety of stakeholders involved in transport of highly perishable foodstuffs and pharmaceutical products in the cold chain. It is extremely important that all participants in this process strictly comply with standards and regulations appropriate to their role in cold-chain logistics. In order to raise the quality of services provided and ensure food safety, many organisations decide to implement a food safety management system compliant with PN-EN ISO 22000:2018-08, which contains requirements for every organisation belonging to the food chain. The document contains general requirements and guidelines for all organisations in the food chain that participate in it directly or indirectly. The standard may be useful for entities such as: food manufacturers, retailers, companies and organisations providing food, transport, storage and distribution services, farmers, feed and pet food manufacturers, persons harvesting wild plants and animals, and for other entities involved in this industry, including suppliers of disinfectants and other materials that may come into contact with food.

Temperature distribution testing – mapping / hygiene

When discussing cold-chain issues one should also not forget the hygiene requirements of the so-called HACCP system resulting from Regulation (EC) No 852/2004 of the European Parliament and of the Council of 29 April 2004; the regulation addresses extremely important general principles for food business operators regarding food hygiene and applies to all stages of production, processing and distribution of food and to exports. Among other things it emphasises the requirement to maintain the cold chain for food that cannot be safely stored at ambient temperature, in particular frozen food, and the requirement for temperature control for foodstuffs.

SUMMARY

The issues raised in the article concern one link of the cold chain, namely transport, and even with regard to this one link, due to the complexity of the topic and availability of technological solutions, do not exhaust it. The cold chain includes not only transport; its other links include cooling of the obtained product (produced or obtained e.g. after harvest or slaughter), storage and warehousing, sale, including very often product display. In the cold chain, depending on the product, other parameters may also be defined, for example humidity, transport or storage time. It should also be remembered that companies performing transport of temperature-sensitive products, in addition to requirements related to temperature maintenance, must hold a number of other certificates and permits (vehicles approved by the County Sanitary Inspectorate, registration with the Chief Veterinary Inspectorate in the case of transport of meat and products of animal origin, etc.). Very often a system monitoring and recording temperature is also required, especially for transport of pharmaceuticals and frozen products.

AUTHORS

MSc Eng. Dorota NIEDOJADŁO MSc Eng. Bogdan SZCZEPAŃSKI MSc Eng. Miłosz GRATKOWSKI

REFERENCES

Act of 19 July 2019 on counteracting food waste. Journal of Laws 2019 item 1680. Agreement on the International Carriage of Perishable Foodstuffs and on the Special Equipment to be Used for such Carriage (ATP), done at Geneva on 1 September 1970. Journal of Laws 2022 item 1824 Agreement on the International Carriage of Perishable Foodstuffs and on the Special Equipment to be Used for such Carriage (ATP) (version of 1 June 2022) Materials of the Central Refrigeration Centre COCH in Kraków PN-ISO 668:2015-08. Series 1 freight containers – Classification, dimensions and ratings PN-EN 17066-1:2019-10 Thermally insulated means of transport for temperature-sensitive goods – Requirements and testing – Part 1: Containers PN-ISO 1496-2:2020-10 Series 1 freight containers – Specification and testing – Part 2: Thermal containers ISO 8058:1999 Air cargo. Insulated container. Thermal efficiency requirements Regulation of the Minister of Health of 13 March 2015 on the requirements of Good Distribution Practice GDP PHARMA – 03/2023 - Requirements for Good Distribution Practice (GDP) with regard to means of transport, containers, chambers and elements of their additional equipment used for carriage and/or storage of pharmaceutical and sensitive products under controlled/regulated temperature. Normative requirements of the Central Refrigeration Centre “COCH” in Kraków, ed. 1 of 07.09.2023 PR-06 – Certification of Good Distribution Practice (GDP) with regard to means of transport, containers, chambers and elements of their additional equipment used for carriage and/or storage of pharmaceutical and sensitive products under controlled/regulated temperature. Certification programme of the Central Refrigeration Centre “COCH” in Kraków, ed. 8 of 07.09.2023. Good Distribution Practice (GDP). Website of the Central Refrigeration Centre “COCH” in Kraków. Source: / PKN-DIN SPEC 91323:2019-08. Commercial vehicles with temperature-controlled cargo space used for distribution of pharmaceutical products (for human or veterinary use) -- Guidelines for qualification Warczak, W., Szczepański, B., Bednarczyk, L., Niedojadło, D., Kurcz, L.: Temperature-controlled means of transport intended for distribution of pharmaceutical products – requirements according to PKN-DIN SPEC 91323. Chłodnictwo: organ of the Chief Technical Organisation, 2020, 55(1), pp. 3-8. PN-EN ISO 22000:2018-08 Food safety management systems – Requirements for any organisation in the food chain. Regulation (EC) No 852/2004 of the European Parliament and of the Council of 29 April 2004 on the hygiene of foodstuffs (OJ L 129, 30.4.2004, p. 1) IATA – International Air Transport Association. Website. Source: https://www.iata.org/ UNECE – United Nations Economic Commission for Europe. Website. Source: https://unece.org/ Food Safety. European Commission. Source: https://food.ec.europa.eu/ index_pl Article published in the journal Chłodnictwo i Klimatyzacja 8-9/2023