A multiple combinations of oxides of nitrogen (N2O, NO, NO2, N2O4, N2O3, N2O5) with nitrogen dioxide (NO2) being the principal hazardous nitrous gas.

Ohms is a measure of the electrical resistance of a circuit.

To calculate the resistance of a firing cable you need to know the length of the cable and the number of ohms per 100m.

Example if a firing cable is 1,600 meters long with a resistance of 1.4 ohms for every 100m the resistance is 16 x 1.4 = 22.4 ohms

The symbol for ohms is Ω

Operating Standards describe the process outcomes or end state after a transition.

The end state should usually be defined as a target and a tolerance.

For example an operating standard for charging explosives may be:

 - A minimum of 95% of holes are to be loaded to design kilograms +/- 10% and

 - All holes with less than the minimum stemming are to be recorded and reviewed in regards the planned clearance distance.

The operating standard does not define the steps to complete the process, rather it just defines the required outcomes.

Operating standards are appropriate when the outcomes are critical but the exact sequence to deliver this is not critical.

Detonating cord with an outer wrapping of spun yarns.

Overwrapped cord has a braided appearance and is easier to tie knots in.

Overwrapped cord.

Plastic finished cord.

High temperature detonating cords are limited by the explosives properties and the jacket material.

Chemically – the gain of oxygen by a molecule, atom or ion.

O2 Balance refers to the balance between the oxidiser and the fuel in an explosive.

Oxygen balanced explosives are mixed such that all the oxidiser and the fuel are used up in the detonation.

Where explosives are not O2 Balanced a reduction in energy and an increase in blast fume are likely outcomes.

Explosives that is pre packaged into plastic, card or paper tubes.

Two or more (straight) lines, (flat) surfaces equally distant from one another at all points.

The PCF tube is a hollow plastic tube, open at one end which can then be filled with the powdered smokeless propellant and then closed with a small cap. The other end is machined into a wedge to lock into the stemming, and to seal the hole when inserted for ignition. In the cap there is an entry port for insertion of an electric match, which is the means of detonation. This heat ignites the propellant. As there are not the crushing effects of compressive breakage as with explosives, dust and fines are significantly reduced. As the rock requires less energy to break in tension than compression, a much smaller energy input is recquired. A 200 g charge of PCF blasts the same volume of rock as does 1.2 kg of explosive charge, whilst releasing one tenth of the energy. The product has been found to be particularly useful in deep South African mines as it’s low toxicity reduces re-entry time in these hard to ventilate mines thus improving productivity by up to 40 % (Minesite News, 2000). Some gas is produced from the combustion of the cartridge, for PCF, the majority of the gases produced are carbon dioxide, water, nitrogen, carbon monoxide and hydrogen. The main problem gases which are detectable are carbon monoxide, and nitrous oxide which also occurs at low levels. The addition of a very small amount of ANFO prill does increase the toxic fumes from the product, but still below minimal levels in modern ventilation systems. This gives the product a little extra power to fragment the rock. The product also has the ability to enable users to have more control over the accuracy of the excavation profile and drive perimeters. PCF has also been used in floor stripping, back stripping and side wall stripping in a number of mines in Australia, particularly when a larger equipment size is required and minimal disruption to underground operations is essential. By altering the position of the charges in the holes the products flexibility allows for the rock to be fractured or split. PCF can also be used for the clearing of block grizzlies, crushers or chutes, or anywhere else where oversize is a problem.
The classification for PCF is 1.4S pyrotechnic, as an added safety precaution, the electric match used for detonation is inserted right before firing.