Fumigated shipping containers — venting before unpacking by end user

Hazards

Employers must assess the risks for each identified hazard. When assessing the risk, the degree and likelihood of employees or other people being exposed to the hazards must be considered.

The presence of unsafe levels of methyl bromide (MeBr) is a hazard to the health and safety of persons involved in unpacking shipping containers.

Shipping containers that have been fumigated and ventilated by fumigators may still contain a significant quantity of methyl bromide (MeBr) due to poor venting procedures, desorption or entrapment of the gas in the packaging and materials used to secure the container cargo (dunnage). This may present a risk to persons involved in unpacking these containers.

Risks

MeBr affects the central nervous system. 

Depending on the level of exposure, breathing in MeBr may cause:

• dizziness
• drowsiness
• headache
• nausea
• blurred vision
• numbness
• tremors
• speech defects
• fluid in the lungs (pulmonary oedema)
• prostate cancer

Employers must ensure that employees are not exposed to levels of MeBr above the current Workplace exposure standards for airborne contaminants (2024). Current limits are 5 ppm (parts per million).

Controlling risks

Where there is a risk to health and safety, employers must, so far as is reasonably practicable, eliminate the risk. If it is not reasonably practicable to eliminate the risk, the risk must be reduced, so far as is reasonably practicable. 

Employers must eliminate or reduce, as far as is reasonably practicable, the exposure to MeBr by employees or contractors who unpack shipping containers.

Use the hierarchy of control to identify and put in place the highest order of control. In many cases several control measures may need to be used to reduce the risk, so far as reasonably practicable.

Check for fumigation

The following control measures should be used when controlling exposure to unsafe levels of MeBr:

• Check if the container cargo, dunnage and wood packaging have been fumigated.
• Try to find out if the container was fumigated in Australia or overseas.
• Check for any fumigation warning notice on the shipping container such as the example in figure 1.
• Check for certification of MeBr fumigation of wood packaging and dunnage.
• Check for a shipping container clearance certificate that records the date and time of ventilation and level of MeBr achieved (less than 5 ppm).

If in doubt, treat the shipping container and everything inside as fumigated.

Ventilating fumigated containers

1. Place the shipping container in an open area with good natural ventilation.
2. Set up barricades and warning signs around the entrance to the container to prevent unauthorised access.
3. Vent the container by opening the container doors to allow natural ventilation for a short period, or use a blower fan.
4. When opening doors, always ensure to take reasonable care to avoid exposure to any MeBr that may be present. This should include the use of relevant personal protective equipment (PPE) such as breathing masks with filters.
5. Before entering the container, vent the container using mechanical ventilation — blowing or extraction — for approximately 30 minutes. The time will depend on the nature of the goods and how the container is packed. The time may be reviewed for a particular workplace based upon the types of loads received and any air monitoring readings obtained.

Fans or mechanical ventilation is recommended if there is:

• highly absorptive material, for example, wood, nuts, seeds or foam rubber
• packaging that may trap the fumigant, for example, boxes or plastic wrapping
• little natural air movement around the container
• tightly packed containers restricting natural airflow.

If mechanical ventilation is not practicable or available, vent the container using natural ventilation. General fumigation procedures recommends 12 hours. Refer to AS 2476-2008: General fumigation procedures.

Following ventilation, before entry, test the air inside the container using suitable air testing equipment to ensure that the MeBr level is below 5 ppm.

If the container is tightly packed, partially unpack the container wearing appropriate PPE and allow further venting for a short period. Repeat this process until unpacking is complete.

Air testing equipment

If shipping containers are regularly handled, a range of equipment is available to test for MeBr — consider using this equipment.

The detection sensitivity of air testing equipment can vary, as shown in the following table.

Halide leak detection lamp

A halide leak detection lamp is simple to use and does not need calibration.

A halide leak detection lamp works on the principle that a flame in contact with a clean piece of copper will burn with a green to blue flame if vapour of an organic halide is present in the surrounding air. They cannot be relied upon for accurate quantitative measurements.

Halide leak detection lamps are useful for indicating the presence of immediately dangerous concentrations, for preliminary checking the effectiveness of aeration.

A Halide leak detection lamp or any electrical equipment not intrinsically safe must not be used where flammable goods are present.

Intrinsic safety is a protection technique for safe operation of electrical equipment in hazardous areas. The technique limits the energy, electrical and thermal, available for ignition — preventing sparks and keeping temperatures low, which can help to prevent explosion in a flammable atmosphere.

Information, instruction, training and supervision

Employers must provide any necessary information, instruction, training or supervision to relevant employees so that they can do their work in a way that is safe and without risks to health. 

Provide information, instruction, training, or supervision about how employees can unpack shipping containers safely.

This information includes:

• the systems of work and risk control measures used at the workplace
• the safe working procedures for inspecting and unpacking fumigated shipping containers 
• the use of any MeBr testing equipment.

Employer duties

Employers have duties under the Occupational Health and Safety Act and Regulations. 

Occupational health and safety – your legal duties provides an overview of employer and employee responsibilities under the Occupational Health and Safety Act 2004.

Consultation

Employers must also, so far as is reasonably practicable, consult with employees, contractors, labour hire workers and any health and safety representatives (HSRs) about health and safety matters.

This includes consulting when:

• identifying or assessing hazards or risks
• making decisions about risk control measures. 

You must give your employees and any HSRs information about health and safety matters that affect them or are likely to affect them. Give them enough time to consider, discuss and then give their feedback.

If it is reasonably practicable, you must provide the information to any HSRs a reasonable time before it is provided to employees.

Information should be in a form that employees and HSRs can easily understand. They may need information such as technical guidance about workplace hazards and risks. For example, information about equipment and substances. They may also need information about how work is organised. For example, systems, reports, procedures and guidance material.