Sandra is a skilled chemist with over 35 years of experience in analytical chemistry, particularly with 10 years of experience in various areas of food testing. She joined the Government Laboratory in 1978 and retired in 2004. She has extensive experience in accreditation and laboratory management system including: 4 years of experience as HOKLAS accreditation officer and another 9 years of experience as HOKLAS lead assessor and assessor conducting over 200 assessments under different test categories. She is conversant with various accreditation criteria and uncertainty evaluation and has assisted in drafting of 4 HOKLAS Supplementary Criteria and acted as co-chairman of microbiological group of APLAC for formulation of policy for measurement uncertainty.