Dune dynamics: from field measurements to numerical modelling. Application to bathymetric survey frequency in the Calais-Dover Strait.

The present invention relates to an aerosol hair spray package having reduced volatile organic compound emission during the useful life of the package. A hair spray composition (3, 25) is packaged in either a self-propelled aersol hair spray package (1) or a pump spray hair spray package (20) containing a low delivery rate discharge means (6,23). The hair spray composition (3, 25) contains a combination of at least two polymers in weight ratios of 99:1 to 1:99 differing in weight average molecular weight by at least 1.5, one of which is required to have a number average molecular weight of at least 100,000. This blend of polymers combines with the low delivery rate discharge means-0.2-0.38 grams per second for the self-propelled hair spray package (1) and 0.06 to 0.012 grams per pump stroke for the pump spray hair spray package (20)-to provide an atomized hair spray composition having a volume mean particle size of 60+/-12 microns for package (12) and 73+/-13 microns for package (20). These packages are considerably smaller in size than conventional hair spray packages having higher discharge rates, but provide substantially the same number of uses per container as the larger size conventional hair spray packages, thus effecting reduced cost and environmental impact advantages.