A quick reference for setting temperature for reefers carrying dangerous goods. Users must refer to individual entries in IMDG Code and section 7.3.7, Cargo transport units under temperature control, for actual shipments.

This is in accordance with IMDG Code amendment 38-16.

• Class 2.1, Flammable Gas, – If flashpoint is less than 23°C c.c and not requiring temperature control substances must be pre-cooled to and transported at a control temperature of at least 10°C below the flashpoint. (not applicable for reefers fitted with explosion proof electrical fittings)
• Class 3, Flammable Liquid – If flashpoint is less than 23°C c.c and not requiring temperature control substances must be pre-cooled to and transported at a control temperature of at least 10°C below the flashpoint. (not applicable for reefers fitted with explosion proof electrical fittings)
• Class 4.1, self-reactive substances – Which require temperature control – reefer must be set at or below control temperature indicated in table 2.4.2.3.2.3, IBC520 or Tank instruction T23 on as approved by competent authority
• Class 4.1, polymerizing substances – When Self-accelerating polymerization temperature (SAPT) is
• 20°C or less in single packaging and IBCs control temperature to be set at or below 20°C below SAPT
• over 20°C to 35°C in single packaging and IBCs control temperature to be set at or below 15°C below SAPT
• over 35°C C in single packaging and IBCs control temperature to be set at or below 10°C below SAPT
• < 50°C in portable tanks control temperature to be set at or below 10°C below SAPT
• Class 5.2, Organic Peroxides – Which require temperature control – reefer must be set at or below control temperature indicated in table 2.5.3.2.4, IBC520 or Tank instruction T23 on as approved by competent authority

For class 4.1, self-reactive substances and class 5.2 organic peroxides the actual transport temperature may be lower than the control temperature but must be selected so as to avoid dangerous separation of phases.

• Calcium Hypochlorite – Temperature control is not required by IMDG Code however if shipped in reefers control temperature to be set at 10° C (Contact your P&I club for further guidance)