Habitat Loss                                         A grassroots movement towards orchid conservation


orchid species alan stephenson
Alan W Stephenson's  Orchid Species of Shoalhaven, NSW Australia

A book about Australian orchids, habitat,  and conservation

Available from:
[email protected]

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Alum Mt. fire 2009

After the Alum Mt. fire 2009

After the Alum Mt. fire 2009

Orchid Habitat Loss 

Fire Retardant Chemicals Effect on the Enivornment text by Alan Stephenson

Although fire retardant chemicals were not used to control or extinguish the Aum Mt fire (2009), recent fires in Victoria during the summer (2008-2009) saw large amounts of retardant used. I was initially concerned about the use of this chemical and its immediate and long term effect on terrestrial orchids, although that would not have been a concern to those using it or those whose homes and properties would have been protected from the intense and widespread fire which burned so much area over several weeks last summer. The retardant is a fertiliser based preparation and has been used for about 30 years. Examples of long term retardants are Phos-Chek D75 and Phos-Chek D75R. These are mostly ammonium, diammonium sulphate and ammonium phosphate with thickeners (guar gum) with corrosion inhibitors (for aircraft safety) and frequently a red pigment made from iron oxide is used to enable spraying teams to see the area sprayed. The short-term examples are; Ansul Silv-Ex, Angus ForExpan S, Fire Quench, 3M Firebreak and Phos-Chek WD-881. Short-term types are a combination of wetting agents and foaming chemicals mixed with water which allows easier surface penetration. Following evaporation of the water the chemical prevents re-ignition of vegetation until it is removed by rain or erosion.


Little research has been undertaken to determine the environmental effects of fire retardant use but current information indicates no significant effects on birds or mammals, however in Australia long-term fire retardants have been observed to cause effects on some species of native plants, leading to low level damage to new growth and the concentrated powder can cause minor respiratory irritation to those workers who are may handle it. Water plants and animals are more sensitive to the effects of fire retardants and foams can be toxic to aquatic life and pilots try to avoid spraying water bodies.

Alan W Stephenson
National Conservation Officer
Australasian Native Orchid Society (ANOS)