His almost unique experience with this new material cellulose acetate brought him an invitation to take the post of chief chemist of the Non-inflammable Film Company in 1928. When that company failed in 1931 he set up in business on his own, selling research which he backed up with practical investigation, and operating, initially, from a laboratory in an extension to the garage of his home in
Ewell, Surrey. At first much of his work consisted of acting in an advisory capacity in lawsuits involving patent infringement and other such matters. The small business gradually prospered, in no small part as a result of his Foresight in anticipating industry's needs in promoting the testing and analytical services into a facility serving industry at large. After an expansionary move to Ashtead, Surrey, his company eventually merged with the Fulmer Research Institute. It had a staff of 150 when he relinquished control. Yarslev was very active in the plastics and polymer group of the Society of Chemical Industry in the 1930s and became its chairman for a year in 1938. He supported the fledgeling Plastics Institute from its beginning in 1931 and became its president From 1953 to 1955. He was chairman of the Plastics Industry Education Fund For many years. For 25 years from 1935, Yarsley was a monthly contributor on plastics to The Times Review of Industry and the author of several books. The Penguin books he wrote with E.G.Couzens:
Plastics in 1941 and its revisions
Plastics in the Service of Man and
Plastics in the Modern World became bestsellers of their type and gave many a non-plastics scientist and engineer, and indeed many a layman, an excellent insight into the nature and characteristics of these mysterious materials. Yarsley strove for their acceptance as materials in their own right and not just as substitutes or ersatz products, to be replaced by others when times got better. ==Awards==