Product Safety Report: Diferro Calenders - Sublimation Calender Presses – All Models featuring a sealed oil-filled heated drum – Including DP-series, MP-series, DM-series, DE-series, DR-series, DX-series, DF-series  (2402-0018)
Source: gov.uk (2025-10-10)

Product Safety Report for Diferro Calenders - Sublimation Calender Presses – All Models featuring a sealed oil-filled heated drum – Including DP-series, MP-series, DM-series, DE-series, DR-series, DX-series, DF-series presenting a serious risk of explosion and fire.

Product: Diferro Calenders - Sublimation Calender Presses – All Models featuring a sealed oil-filled heated drum – Including DP-series, MP-series, DM-series, DE-series, DR-series, DX-series, DF-series

Hazard: The product presents a serious risk of explosion and fire.

Corrective action: In light of a second explosion and fire, the Health and Safety Executive (HSE) are now updating advice to users of all Diferro calender presses with a sealed oil-filled drum. For further information, please see the PDF linked below.

Product information

Hazard

Sublimation calender presses within the scope of the corrective action have been identified as presenting a serious risk of explosion and fire.

Two catastrophic Boiling Liquid Expanding Vapour Explosion (BLEVE) incidents have now occurred involving Diferro machines. Evidence suggests that in both cases the machines had been left unattended and connected to the electrical power supply and that uncovenanted and uncontrolled heating of the oil-filled drum has occurred. The built-in temperature control system has then also failed to operate to prevent overheating and over-pressurisation of the sealed drum (roller). No external source of heat has been present to cause the overheating of the oil-filled drum.

There is potential for system control failure to result in unplanned uncontrolled heating of the oil-filled drum at any time when the machine is connected to the electrical power supply, including when left in standby mode after the normal cool-down cycle has completed and when using weekly programme function (timer mode). If the machine is unattended when this occurs failure to promptly shut down and isolate from the power supply may result in overheating and catastrophic failure of the drum and a BLEVE. The potential explosion and any subsequent fire is likely to cause catastrophic damage to the building and its surroundings, with potential for multiple fatalities and significant property destruction.

The original Programmable Logic Controller (PLC) within the control system of these calender presses does not meet any required safety performance level. There is no independent secondary temperature monitoring and control system.

The product does not meet the requirements of the Supply of Machinery (Safety) Regulations 2008.

Corrective action
- GB suppliers have been asked to stop selling Diferro calender presses containing a sealed oil-filled heated drum until further notice.
- These machines must not be operated using the weekly programming function.
- These machines must not be left unattended whilst connected to power.
In light of a second explosion the Health and Safety Executive (HSE) are now updating advice to users of all Diferro calender presses with a sealed oil-filled drum.

The HSE instructs users to cease operating these machines until a second, independent Safety-Related Control System (SRCS) has been fitted. The second SRCS is required to monitor the calender’s drum temperature and must be designed, installed, and validated in accordance with safety standard BS EN ISO 13849 Parts 1 and 2. Details of the requirements are given in Appendix 1. Appendix 1 is included in the PDF linked above.

Users will also need to implement systems of work to ensure that the primary control system and this secondary SRCS are maintained and tested at appropriate intervals. The machine should be taken out of operation in the event of any anomalies in temperature monitoring/control or upon activation of any alarms or the secondary SCRS. Use should only resume after the cause of the alarm or SCRS activation has been established and rectified.

If users deem the continued operation of these machines to be essential whilst they arrange installation of a second SCRS, they must ensure that the machine is attended and monitored at all times when connected to the electrical power supply. This includes standby, pre-heating, normal running, and the cool-down cycle stages. Details of the precautions and system of work required are given in Appendix 2. Appendix 2 is included in the PDF linked above.

The interim measures described in Appendix 2 are considered to be short-term emergency arrangements which, if correctly implemented and managed will reduce the likelihood of fire and explosion, but cannot be relied upon as a long-term solution.

The installation of the SCRS should be completed immediately, and no later than six weeks from the issuing of this alert.

HSE has contacted all known users to share the original product alert (04/04/24) and will continue to share all revisions to this alert.

If you own or operate a Diferro calender press with a sealed oil-filled heated drum and have not been contacted by HSE, or if you have any questions about this Product Safety Report, you can contact HSE by completing an enquiry at https://www.hse.gov.uk/contact/ask-us-about-health-and-safety.htm

These machines must not be supplied onwards to any other user without providing copies of this and any subsequent alert relating to the use of Diferro calender presses with a sealed oil-filled drum.

Users should contact their local fire authority and make them aware of the presence of these machines in their premises, including the possibility of a BLEVE. They should seek advice on the appropriate arrangements for fire safety and emergency evacuation and response.

Users may wish to contact their insurers to discuss the continued use of these machine in their premises.

Additional information

PSD case number: 2402-0018

Notified by: Health and Safety Executive