Some forms of the chemical are odour-free; others have a strong odour.

Then, when the inevitable power cuts occur, they will have odour-free candlelight.

It is clean and relatively odour-free.

A far cry from the choking, firewood kitchen next door, the biogas kitchen is odour-free and smokeless.

Known as a "wash and wear" dog, the Australian Cattle Dog requires little grooming, and an occasional brushing is all that is required to keep the coat clean and odour-free.

One of the distinctive feature of Pathak's project lies in the fact that besides producing odour-free bio-gas, it also releases clean water rich in phosphorus and other ingredients which are important constituents of organic manure.

The dilution factor: the number of times a sample of the odorous gas has to be diluted with odour-free air before 50 per cent of the panel of the six observers will just NOT detect an odour.