Abstract: A gas sensing system is provided for the detection of gas concentrations in a flowable medium. The gas sensing system has a gas permeable membrane structure to separate the flowable medium from a chamber where a gas sensor is positioned for detecting the gas concentration in the chamber. The sensor has predetermined environmental operating ranges and the system has a heat drain with a heat sink to maintain the temperature of gas in the chamber within the operating ranges, together with gas nozzles leading into the chamber to purge gas in the chamber and to maintain the gas concentration from exceeding the sensor operating range.

Abstract: Compositions are provided which protect keratinous material such as skin and hair from the deleterious effects of detergents and adverse climatic conditions. Said compositions contain a modified protein and a surface active agent.

Abstract: Detergent Compositions having a protective effect on keratinous material incorporate a proteinaceous material whose primary amino or carboxylic acid side chain groups have been modified by reaction with C.sub.1 -C.sub.7 acyl- or alkyl- group-containing materials respectively to give a modified protein of isoionic point (pI) less than pH 6. Granular, bar and liquid detergent formulations embodying the invention are disclosed.