There are few restrictions on the carriage of dangerous goods in limited quantities by road and rail (ADR/RID). Here Richard Masters reviews the IMDG Code’s additional requirements for documentation and container marking for maritime transport that do exist.
There are several advantages for a shipper when shipping dangerous goods as limited quantities (LQs):
virtually no IMDG Code stowage or segregation restrictions on ships
reduced ADR documentation requirements
no requirement for an ADR-trained driver hauling LQs by road in Europe
less expensive packaging
standardised (therefore cheaper) package marking and labelling requirements.
What goods can be shipped as LQs?
In general, dangerous goods of Packing Groups II (medium risk) and III (low risk) of hazard Classes 3, 4, 5, 6.1, 8 and 9, plus some small arms ammunition of Class 1 and some gases of Class 2 — including aerosols — are eligible to be shipped as LQs. However, the capacity/mass of the inner receptacles must be below a threshold limit specified in the IMDG Code Dangerous Goods List if the goods are to be shipped by sea (ADR/RID Dangerous Goods List if the goods are moving by road and rail only).
High risk hazard goods of Packing Group I, most explosives, most gases and Class 7 radioactive materials cannot be shipped as LQs regardless of the size of the inner receptacles.
Typically, high volume, low hazard dangerous goods for retail sale (such as household cleaners, personal care products, garden weed and pest control products) are packaged so they are eligible for carriage as LQs. This enables shippers to benefit from maximum relaxation of the transport regulations.
Packaging rules for LQs
Limited quantities must be packaged in combination packages with receptacles contained in an outer package. Packaging does not have to meet the most stringent standards of UN-tested dangerous goods packages, but must be suitable for purpose. Maximum mass of the outer package must not exceed 30kg. Shrink-wrapped trays are allowed (typically for aerosol retail display) but the maximum mass for these is 20kg.
Receptacle size limitations
For each substance the IMDG Code states the maximum size inner receptacle that is allowed as LQs. This can be as small as 25ml/100 grams or as much as 5l/5kg. The more volatile or aggressive the substance, the smaller the maximum receptacle package quantity that can qualify as LQs.
The receptacle size limit for each UN Number can be checked in Column 7a of the IMDG/ADR Dangerous Goods List. It is shown as capacity in litres for liquids and gases, and mass in kilograms for solids. Each substance has its own limited quantity receptacle threshold size limit regardless of class, so Column 7a has to be consulted for every individual substance.
Example 1: UN 2021, CHLOROPHENOLS, LIQUID, 6.1, LQ threshold 5l
UN 2023, EPICHLOROHYDRIN, 6.1, 3, LQ threshold 100ml
For road, sea and rail transport only the LQ mark (see Figure 1, below) is required on packages (side length 100mm). The air LQ mark (which has the letter “Y” in the centre) is also acceptable for road/sea.
Cargo transport units (CTU) restrictions?
No artificial limit, just the maximum plated cargo weight capacity of the container or the vehicle.
Segregation in a CTU
There are no segregation restrictions between packages of dangerous goods in LQs, or between packages of dangerous goods in LQs and other dangerous goods, by road, rail or sea. Mixed packing of two/more receptacles (ie segregation) within an outer package, however, must follow the normal rules.
Documentation for LQs
For a sea journey, a dangerous goods note must be provided that fulfils all the requirements of the IMDG Code for conventionally packed dangerous goods in the normal way. It must include a signed packing certificate, the gross quantity of each UN Number, description of packaging, the shipper’s signed declaration describing the UN Number, Proper Shipping Name, Class, sub-risk, Packing Group, etc, in the normal way, plus the words “LIMITED QUANTITY” after the substance/article description. Shipping lines will not accept any goods as LQs unless the words “LIMITED QUANTITY” or “LIMITED QUANTITIES” are included on the dangerous goods declaration.
CTU placarding and marking
The placarding and marking requirements for containers under IMDG and ADR are aligned. The placarding instructions in the 2010 IMDG Code were confusing, but have been clarified in the 2012 Code and are now clear.
UN 1761, CUPRIETHYLENEDIAMINE SOLUTION, 8, (6.1), marine pollutant
UN 1648, ACETONITRILE, 3, LIMITED QUANTITIES
UN 1950, AEROSOLS, 2.1, LIMITED QUANTITIES
UN 2205, ADIPONITRILE, 6.1, LIMITED QUANTITIES
No class placards or LQs mark is allowed for the goods in LQs. Note that the MP mark would still be required even if the UN1761 was not an MP, but the UN1950 LQ packages were (see IMDG 126.96.36.199.3).
Figure 2 (above) is concerned with consignments with all the dangerous goods in LQs. When all the dangerous goods in a container/vehicle are in LQs, an enlarged LQ mark (250mm x 250mm) must be present on all required sides (all four walls of the container or both sides and the rear of a vehicle). The normal hazard class placards must not be used.
In Figure 3, where consignments with dangerous goods in LQs are also classed as “marine pollutant”, if all the goods are LQ, and one, or more, are classed as marine pollutants, the LQ mark and the marine pollutant (MP) mark is required on all required sides.
Where there is a mixed consignment — dangerous goods with dangerous goods in LQ — only the applicable normal class placard(s) for the goods in conventional packaging must be displayed on the container (see Figure 4, above). Ignore any goods in LQ packages and do not apply LQ marks.