This entry applies to mixtures of butylenes, 1-butylene, cis-2-butylene and trans-2-butylene. For isobutylene, see UN No. 1055. NOTE: For additional information to be added in the transport document, see 5.4.1.2.2 (e).

Cylinders not conforming to the provisions of Chapter 6.2 which are used exclusively on board a ship or aircraft, may be carried for the purpose of filling or inspection and subsequent return, provided the cylinders are designed and constructed in accordance with a standard recognized by the competent authority of the country of approval and all the other relevant requirements of ADN and other conditions are met including: (a) The cylinders shall be carried with valve protection in conformity with 4.1.6.8; (b) The cylinders shall be marked and labelled in conformity with 5.2.1 and 5.2.2; and (c) All the relevant filling requirements of packing instruction P200 of 4.1.4.1 of ADR are complied with. The transport document shall include the following statement: "Carriage in accordance with Special Provision 662".

For each member of the crew, a pair of protective goggles, a pair of protective gloves, a protective suit and a suitable pair of protective shoes (or protective boots, if necessary). On bord tank vessels, protective boots are required in all cases.

A flammable gas detector with the instructions for its use.

A breathing apparatus ambient air-dependent.

Holds containing these substances shall be ventilated whith the ventilators operating at full power, where after measurement it has been established that the concentration of flammable gases and vapours given off by the cargo exceeds 10 % of the LEL. The measurement shall be carried out immediately after loading. A control measurement shall be repeated after one hour. The results of the measurement shall be recorded in writing.