Handling explosives at ports

This bulletin provides the legislative requirements for handling explosives at a port in Queensland, in accordance with Part 4, Division 5 of the Explosives Regulation 2003 (the Regulation). The information in this bulletin includes the process for approval of explosives limits at a port and the requirements for the safe and secure handling, movement and transport of large quantities of explosives through a port.

Adherence to the requirements of this information bulletin is a condition of the Chief Inspector of Explosives approval of explosives limits for a port.

Approved explosives limits are a legislative requirement, as some ports are inappropriate for the safe and secure handling of any quantity of explosives due to the proximity to populated areas, essential infrastructure or other protected works and the unacceptable risk that therefore exists from potential incidents involving explosives at those ports.

Approved explosives limits

To be granted approved explosives limits, a port authority or port operator applies to the Chief Inspector of Explosives where the quantity of explosives are, or are proposed to be, handled at the port in the following quantities:

1. For explosives of Class 1
   1. Hazard Divisions 1.1, 1.2, 1.5 and 1.6 – more than 250kg
   2. Hazard Division 1.3 – more than 2000kg
   3. Hazard Division 1.4 – more than 400t
2. For a precursor (e.g. ammonium nitrate emulsion (ANE)) – more than 25t
3. For any other explosive (e.g. ammonium nitrate (AN), AN fertiliser and calcium ammonium nitrate (CAN)) – more than 400t.

The Regulation requires compliance to Australian Standard AS 3846:2005 The handling and transport of dangerous cargoes in port areas (AS 3846) for the handling of explosives through a port.

Explosives import and/or export

Under Section 54 of the Regulation, a person authorised to import or export explosives must do so at a port that has approved explosives limits. The importer or exporter must confirm with the port authority or port operator that the port has approved explosives limits and the quantity of explosives to be imported or exported does not exceed the approved explosives limit that may be handled at that port.

Port authority or port operator handling explosives

Under Sections 60 of the Regulation, a port authority or port operator is responsible for ensuring that where quantities of explosives are in excess of those outlined in paragraph 4 above, that they have written notice of approval from the Chief Inspector of Explosives and the following applies:

1. The port authority or port operator ensures that explosives are not handled unless there are approved explosives limits for the port and the quantity of explosives is within those limits.
2. The explosives are handled in accordance with AS 3846 or alternative safety measures for the standard (Note: Alternative safety measures must be in writing and must achieve a level of risk that is equal to or less than that achieved by the standard, see section 9 of the Regulation).

Approval of explosives limits

Where a port authority or port operator wishes to have approved explosives limits established for a port for which the authority is responsible, the process to be followed includes the following:

1. Risk and security assessments be carried out on the port indicating, for the relevant berths within the port, the types of explosive and the maximum amounts that may be handled while maintaining an acceptable level of risk and security at the port.
2. The port authority, based on the above risk and security assessments and any other relevant information, decides on the explosives limits the port seeks to handle at any berth.
3. The port authority submits a written document (explosives limits document) to the Chief Inspector of Explosives for approval including the explosives limits proposed and the safety and security risk assessments carried out.
4. The Chief Inspector of Explosives may approve, with or without changes or conditions, or refuse the explosives limits.
5. If approved, the Chief Inspector of Explosives will provide a notice of approved explosives limits to the port authority or port operator (see Sections 61 and 62 of the Regulation).

Risk assessment

The explosives limit document provided to the Chief Inspector of Explosives for approval includes a risk assessment. The risk assessment process is to be documented and acceptable to the Chief Inspector of Explosives.

The risk assessment includes compliance with AS 3846 or alternative safety measures. AS 3846 requires the following additional studies be undertaken:

1. A documented risk assessment for variation to AS 3846 (section 2.2 of AS 3846)
2. A safety management system (section 2.2 of AS 3846)
3. An emergency plan (section 2.2 of AS 3846)
4. A fire safety study with advice sought from the relevant fire authority (section 10.1 of AS 3846)

Table 4.2 of AS 3846 details the separation distances required to protected places for Class 1 explosives.

Separation distances for AN, AN fertiliser and ANE are calculated according to the formula in this section. Where a port is located adjacent to a dwelling, school, hospital, town environment or other vulnerable facility, the separation distance is calculated using the formula:

   D = 10.4Q^1/3

Where D = separation distance in metres and Q = net explosive quantity (NEQ) of explosive in kilograms

The NEQ is calculated according to the following equation:

   Q = mass of explosive (kg) x TNT equivalence x efficiency factor

Note: The following default TNT equivalence, with the efficiency factor of 1.0 included, are accepted by the Chief Inspector: AN or AN fertiliser = 0.32; ANE = 0.70. Alternate TNT equivalences may be accepted by the Chief Inspector where demonstrated on scientific or other grounds.

For example, the separation distance to the facilities described in paragraph 0 for a ship carrying 5,000 tonnes of ammonium nitrate is 1216m. The worked example is:

   D = 10.4 x (Q)^1/3
   Q = 5,000,000 x 0.32 = 1,600,000kg
   D = 10.4 x (1,600,000)^1/3
   D = 10.4 x 116.96
   D = 1216m

This separation distance calculation is based on the decrease in probability and consequence, and hence decreased overall risk of an explosion involving AN, a Division 5.1 dangerous good, as compared to a Class 1 explosive. The risk of detonation of AN is given, but there are several mitigating factors to prevent or decrease the severity of detonation of AN that cannot be considered for a Class 1 explosives. AN usually requires some form of contamination (incompatible material such as combustible material or certain metals) for AN to sustain burning and lead to decomposition and detonation.

Provided adequate security controls are in place, the most likely scenario leading to a detonation of AN is a fire. Such an event gives time to evacuate personnel from the area to a safe location, provided the initiating time of the fire is known. Given active monitoring of the ship and loading or unloading area, the time a fire involving AN begins should be known and these controls can be incorporated into the emergency plan.

Where compliance with AS 3846 or the separation distances for Class 1, AN, AN fertiliser or ANE cannot be met, the port may apply other risk analysis, namely quantitative risk assessment (QRA), to justify the risk as low as reasonably practicable (ALARP). Consideration will be given when the criteria as outlined in HIPAP 4 (Hazardous industry planning advisory paper no 4 Risk criteria for land use safety planning, January 2011 New South Wales Department of Planning) have been satisfied.

The following criteria from HIPAP 4 are applicable:

Individual risk fatality criteria

Injury risk criteria

Explosion overpressure at residential and vulnerable facilities should not exceed 7kPa at frequencies of more than 50 chances in a million per year.

Societal risk

For port locations where there is potential to create multiple fatalities, societal risks are considered. The indicative societal risk criteria should incorporate an ALARP approach in accordance with section 2.4.3 of HIPAP 4.

Security assessment

The security assessment for a port is in accordance with Schedule 3, Part 1(9) of the Regulation. The security assessment considers and mitigates against the following scenarios: unauthorised access to explosives, sabotage, unexplained loss and theft.

Measures are to be taken to prohibit access to people who do not have an appropriate security clearance and who do not need to be at the port during the loading or unloading activity. A marine security identification card (MSIC) should provide an adequate security check for access to explosives. The port operates under their security management system that will include appropriate security clearance for employees who have unsupervised access to explosives.

Special berth requirements

For a quantity at a port of Class 1 explosives not more than 250t, the ordinary berth requirements of section 4.5 of AS 3846 apply. For berthing of quantities of Class 1 explosives in excess of these limits, the berth is declared a special berth. Section 4.6 of AS 3846 details the requirements to be met for a special berth for Class 1.

A quantity of ammonium nitrate (including AN fertiliser and ANE) not more than the following is considered an ordinary berth in accordance with section 6.4 of AS 3846:

1. 400 tonnes in freight containers
2. 150 tonnes in other packaging (including loose IBC)
3. 25 tonnes for ammonium nitrate emulsion.

Where the port approves the berthing of quantities of ammonium nitrate in excess of these limits, the berth is declared a special berth (excluding calcium ammonium nitrate—CAN). The requirements for a special berth for AN are detailed in Section 6.5 and 6.6 of AS 3846.

The special berth provisions include the temporary relocation of all non-essential persons from the berth (i.e. other than those people required to safely and securely handle, move and transport the explosives from the berth). The following table details the method of calculation of the distance for the restricted area based on different explosives.

Calcium ammonium nitrate

CAN is not classified as a dangerous good and has passed UN tests that indicate its hazard properties do not fit Classes 5.1 or 9. A berth for handling CAN will have a limit approved by the Chief Inspector of Explosives. There is no requirement to declare a berth handling CAN to be a special berth, regardless of the quantity being handled.

CAN is a SSAN and as such all due care is to be taken in the safe and secure handling of the product. Particular attention to the prevention of contamination is important.

Changing approved port explosives limits

The approved port explosives limits are conditional upon the circumstances applicable to the assessment of risk and the calculation of separation distances. If the risk or calculated separation distances are no longer valid, the approved port explosives limits must be reviewed.

The approved port explosive limits can be changed as follows:

1. A port authority may apply at any time to change the approved explosives limits. (Section 63 of the Regulation).
2. The Chief Inspector of Explosives may vary the approved explosives limits if reasonably satisfied they are no longer appropriate for the port. (Section 64 of the Regulation). In such cases, the port authority would be notified with the reasons for any changed limits. (Section 64 of the Regulation).

Any port wishing to confirm its approved explosives limits should in the first instance contact their local Explosives Inspectorate (refer to Explosives Information Bulletin 23).

Authorised by Geoff Downs - Chief Inspector of Explosives

Contact: Manager, Explosives Licensing , +61 7 3199 8057 explosives@dnrm.qld.gov.au

Issued by Queensland Department of Natural Resources and Mines