Using the all closed covering low-temperature method, we successfully made the packaging and sampling of ethylene oxide standard.
Ethylene Oxide ; standards ; Sterilization ; instrumentation ; methods

Objective To assess the difference in human skin color among different geographical regions including Northern,Eastern and Sourthern China.Methods Six hundred individuals from Northern (Beijing),Southern (Shenzhen and Dongguan in Guangdong province) and Eastern (Changzhou in Jiangsu province and Yantai in Shandong province) China were included in this study.A Multi Probe Adapter MPA 9 device was used to measure the skin color of 4 body sites,including forehead,left cheek,left medial forearm,and the back of left hand,of these subjects.The Commission International de l'Eclariage (CIE) L*a*b* values were recorded and individual typological angle (ITA) was calculated.Skin color was rated on a scale from 1 to 6 which was proposed by Chardon et al.The SPSS 16.0 software was used to process these data,and the skin color grade distribution was compared by chi-square test among different geographical regions and body sites.Results Among the 2400 tested sites from 600 subjects,2.96％ were rated as grade Ⅰ,39.88％ as grade Ⅱ,36.58％ as grade Ⅲ,16.96％ as grade Ⅳ,3.63％ as grade V,none as grade Ⅵ.In Northern China,Ⅰ and Ⅱ were the most prevalent grade of skin color (530 sites),while ⅣV and Vwere relatively rare (37 sites); in Eastern China,grade Ⅲ predominated (335 sites),which was followed by ⅣV and V (110 sites); in Southern China,the most common grade was Ⅳ (267 sites),while the rarest grade was Ⅰ (2 sites).The back of the left hand seemed to be the blackest,while the left cheek and left medial forearm the whitest,with significant differences in the distribution of skin color grade between these 4 tested body sites (x2 =106.00,P ＜ 0.01).Conclusions Skin color varies among different geographical regions in China,and among different sites on the human body.