ORGANIC chicken and eggs approved by the country's largest certification body contain a synthetic growth promoter that has been banned by other certifiers and is being phased out in Europe and the US.

And far from being completely natural, there are as many as 36 synthetic substances which are found in organic products sold in Australia.

As the Australian organics industry nudges annual sales of $1 billion, pressure is on growers to produce faster maturing - and bigger - yields to meet consumer demand. An agreement last year by the nation's eight independent organic certifiers to support a new domestic standard has disintegrated as the process of amending the standard exposes disagreements between the largest certifier, Australian Certified Organic, and the industry lobby group, the Organic Federation of Australia.

The Biological Farmers Association, which owns Australian Certified Organic, wants to reintroduce the use of synthetic amino acid isolates which were not allowed in the standards agreement.

The amino acids, such as DL-methionine, promote the growth of livestock and can shave a week off the time it takes for a chicken to go from pen to plate. The amino acids are necessary for a range of issues including adequate feathering and to minimise birds pecking each other. Methionine occurs naturally in some livestock feeds, but producers argue that the levels are not high enough to ensure the welfare of birds.