Abstract: The present invention relates to scrubbers, particularly though not exclusively to scrubbers for treating hydrogen sulfide and mercaptan containing air streams and to scrubber media for use therein. There are provided scrubber media comprising a polycarboxylic acid composition. Also provided are methods of treating a scrubber media by addition of a polycarboxylic acid composition as well as scrubber apparatus containing a scrubber media comprising a polycarboxylic acid composition. Also provided are methods of treating a gas stream by introducing a gas stream into a scrubber media which comprises a polycarboxylic acid composition and a polycarboxylic acid composition for use to extend the operating life of a scrubber media.