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16283 Chemical accident in Papoea new guinea with sodium cyanide
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General accident information
Class/Quality * * * *
Year 2000
Summary A crate of sodium cyanide pellets fell from
Helicopter flying over rugged terrain
Causing environmental damage
Country PNG
Chemicals Sodium cyanide
Cause Management-failure
Fatalities/Injuries 0 / 0
Occurrences or events Burst/Rupture, Clean-up, Drive, Fall,
Management-failure, Management-failure, Management-failure, Pollution/Contamination,
Recover, Release, Remove, Safety-measures,
Safety-measures, Wrong-stowage, Wrong-stowage
Full accident information 
download accident report Click here to view a document containing the full accident information

Date : 2000 0528

Deadly sodium cyanide accidentally dropped (fell) from a helicopter has seeped into a river and villagers in the area have been warned not to drink the water.
Up to 70% of 1E+3/kg of poison pellets had been recovered from dense jungle about 85/km north of the capital, but monsoon rains had washed something like 100 to 150/kg into a nearby river.
A timber crate (wooden box) of cyanide pellets (used in gold processing), suspended below a helicopter as it flew over rugged terrain near the mine, dropped, while being flown to a mine. The box fell from its harness and shattered on impact, spraying (flying) the bullet-sized pellets around the site.
Efforts to recover the potentially lethal pellets were hampered by monsoon rains, sparking fears the cyanide could wash into a local waterways.
The decontamination team had collected into sealed containers all visible cyanide pellets where the incident occurred and this material was being taken to the mine's cyanide deconstruction facilities.
One week after the spill the warning not to drink water potentially contaminated by cyanide was still in force even though the mining company said it had cleaned up the spill.

Recovery and Measures taken to collect and contain any drainage from the area
and monitoring:
Ground Team excavated small trenches on down dip side of the area to contain any drainage from the area.
Emergency team were fitted out with the appropriate emergency gear and breathing apparatus.
Samples were immediately taken of the stream running through the impact site and values of 0.5/ppm and 1/ppm Cyanide was returned. (Plant discharge limits are set at 5/ppm.
The Cyanide box was broken and the reinforced plastic bag holding the cyanide split and some 20% of the total mass of cyanide were scattered down dip. Due to the force involved most of the cyanide pellets were found embedded near the impact site and others some 50/meters away.

Cyanide Recovery:
Cyanide pellets were picked up by hand and shovel and placed in plastic bags. A total
of 12 persons were involved in this operation. Metallurgical personnel and experts
from suppliers of cyanide supervised this team of 12. The team was inducted in safe
handling of cyanide. Recovery of the cyanide pellets was started with scatter zone and
once completed was focused onto actual impact site. Most of the cyanide pellets were
recovered from the impact site and operators of the mine believe that some 95% of
cyanide were recovered.

The emergency services said a warning remained in place that 300 inhabitants of the mountainous area where the spill happened a week ago should avoid drinking or bathing in water drawn from local sources.
Monitoring continued in the following weeks on a daily basis to monitor effectiveness
of the decontamination process. The impact site and scatter zone was carpeted with
Ferric Sulphate; some reacted and turned blue.
All material was transported to the mine and used/disposed off in conventional C.I.L.
gold winning process. Monitoring of the soil at impact site continued and soils removed
for processing in the Mill.
Cause of Accident/Incident as investigated by the Mining Department:
Loading plans was not properly supervised i.e. the straps and load were incorrectly fastened.
Supervisor was not present at the time of loading of cyanide boxes.
Load Masters/Riggers did not receive any course or training to handle dangerous
goods including chemicals and cyanide.
Timber was loaded with cyanide boxes.

Lessons learned (recommendations made by the Mining Department):
Strict supervision and Duty of Care must be undertaken when handling hazardous goods (HAZCHEM) and chemicals that includes cyanide.
Mine operator to conduct training courses on Safe Load Lifting Procedures to all its Riggers and Load Masters by a competent trainer.
Mine operator to engage an Independent Organisation to carry out audit of the
logistic functions at their 2 bases.
Logistics Management at 2 bases needs to be overhauled and upgraded.

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