When we talk about UN-certified 4GV boxes we mean a particular type of packaging (the letter "V" indicates a special packaging in compliance with specific requirements of the legislation) used for the transport of dangerous goods. When these boxes are approved by a valid certification body, they can be used for the transport of dangerous goods by land (ADR), by rail (RID), by waterway (ADN), by sea (IMDG), and by air (ICAO / IATA). Thanks to their features, you can use them for the shipment of objects or inner packaging of any kind for liquid or solid for solid or liquid substances belonging to packing group I (high danger), packing group II (medium danger), or packing group III (low danger).
Unlike 4G boxes, approved with a specific combination of the outer packaging (box) and the specific inner packaging (which cannot differ from the one used during the tests), 4GV boxes do not need to have the inner packaging tested.
However, when it comes to 4GV boxes, it is necessary to respect the indications written on the test report (which can be requested to the packaging manufacturer), such as the maximum gross weight of the inner packaging, the gross weight of the package, the sealing of the box and the minimum thickness of vermiculite between the inner packaging(s) and/or walls, bottom, and lid.
We have mentioned an essential and characterizing element of 4GV boxes, namely vermiculite. But what is it exactly? And why is it traditionally used in combination with 4GV boxes? Let's watch it step by step. First of all, it is an absorbing and cushioning material, given its technical characteristics: it is chemically inert, fireproof, rot-proof, and insoluble in water and organic solvents, it is free from impurities and is sterile.
It is a mineral-based material that, after being processed through exfoliation, comes as scales or grains made of micro-channels and closed cells: these features make vermiculite suitable to absorb shocks and liquids and, therefore, ideal to be used as filling material for packaging. Furthermore, it does not fall into any class of danger for the transport of dangerous goods and is therefore not subjected to the relevant Regulations ADR (by land), RID (by rail), ADN (by inland waterways), IMDG (by sea) and ICAO / IATA (by air).
For its use, it is necessary to consult the packaging approval certificate, the same which also gives information on the minimum distances between the inner packaging and between inner packaging and walls, bottom, and lid of the box. In the UN approval certificate, too, it is indicated that, once the box has been assembled, a polyethylene bag must be placed inside. This will contain all the inner packaging wrapped in vermiculite. These bags are not only a request written on the UN certificate but they are also mandatory according to the law. These bags avoid dispersion of liquids in case of leaking, allowing the vermiculite to absorb them. Furthermore, even if not required by law, it is possible to protect the inner packaging by placing them individually in plastic bags closed with adhesive tape or clamps and then wrapping them with vermiculite.
Why do we recommend the use of bags to wrap inner packaging?
Easy: if vermiculite is subjected to rubbing and erosion (as it happens during transport), it can produce dust that will deposit on all your inner packaging. This is a real trouble, which affects not only the sender who will deliver a dusty product but also the recipient of the dangerous goods who will have to clean all the inner packaging.
To overcome this drawback, special vermiculite-free 4GV boxes have been designed and put on the market. These boxes do not contain that material which, while necessary for the absorption of liquids and shocks, could cause "damages" to the materials contained therein. These boxes are equally UN approved and are suitable for the shipment of dangerous goods according to ADR (by land), RID (by rail), ADN (by inland waterways), IMDG (by sea), and ICAO / IATA (by air) regulations. The "secret" of these boxes is a special kit with alternative materials, which can still perform absorption of liquids and shocks, and eliminate the troubles that vermiculite could cause.
The advantages that derive from it are, therefore, many: