GB/T 7918.2-1987 PDF EnglishUS$135.00 · In stock · Download in 9 seconds
GB/T 7918.2-1987: Standard methods of microbiological examination for cosmetics. Standard plate count Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure
Similar standardsGB/T 7918.2-1987: Standard methods of microbiological examination for cosmetics. Standard plate count---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GBT7918.2-1987 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA UDC 668.58.576.85.07 GB 7918.2-87 Standard methods of microbiological examination for cosmetics - Standard plate count Issued on: MAY 28, 1987 Implemented on: OCTOBER 01, 1987 Issued by. Ministry of Health of PRC Table of Contents1 Method summary... 3 2 Culture medium and reagents... 3 3 Instruments... 4 4 Operation steps... 4 5 Colony counting method... 5 6 Colony count and reporting method... 5 Additional information... 7 Standard methods of microbiological examination for cosmetics - Standard plate count The total bacterial count refers to the number of live bacteria contained in 1 g or 1 ml of cosmetics. Determining the total bacterial count can be used to determine the degree of bacterial contamination of cosmetics, as well as the raw materials, tools and equipment, process flow, operator hygiene used by the production organization. It is a comprehensive basis for the hygienic evaluation of cosmetics. This standard adopts the standard plate count method.1 Method summaryThe types of bacteria contaminating cosmetics are different; each bacterium has its own certain physiological characteristics. The nutritional requirements, culture temperature, culture time, pH value, aerobic properties, etc. during cultivation are different. In actual work, it is impossible to meet the requirements of all bacteria. Therefore, the results measured only include the total number of a group of mesophilic aerobic and facultative anaerobic bacteria grown under the conditions used in this method (cultured at 37 °C for 48 hours on lecithin and Tween 80 nutrient agar).2 Culture medium and reagents2.1 Physiological saline. See GB 7918.1-87 "Standard methods of microbiological examination for cosmetics - General rules". 2.2 Lecithin, Tween 80 - Nutrient agar medium Ingredients. Peptone. 20 g Beef extract. 3 g Sodium chloride. 5 g Agar. 15 g UDC 668.58.576.85.07 GB 7918.2-87 evenly. After the agar solidifies, turn the plate over and place it in a 37 °C incubator for 48 hours.5 Colony counting methodFirst observe with the naked eye and count the number of colonies. Then check with a magnifying glass of 5 ~ 10 folds to prevent omissions. After recording the number of colonies on each plate. Calculate the average number of colonies grown on each plate at the same dilution. If there are colonies in the plate that are connected into sheets or flower-like colonies that spread and grow, the plate should not be counted. If the sheet- like colonies are less than half of the plate, whilst the number of colonies in the remaining half is evenly distributed, THEN, the colony count of this half of the plate can be multiplied by 2, to represent the number of colonies in the whole plate.6 Colony count and reporting method6.1 First, select the plates which have average colony counts between 30 ~ 300, as the range for total colony count determination. When the average colony count of only one dilution falls within this range, the plate colony count is multiplied by its dilution multiple (see Example 1 in the Table). 6.2 If there are two dilutions, meanwhile their average colony counts are both between 30 ~ 300, the ratio of the total colony counts of the two shall be calculated for determination. If the ratio is less than or equal to 2, the mean shall be reported; if it is greater than 2, the smaller colony count shall be reported (see examples 2 and 3 in the Table). 6.3 If the average colony counts of all dilutions are greater than 300, the average colony count of the highest dilution multiplied by the dilution multiple shall be reported (see example 4 in the Table). 6.4 If the average colony counts of all dilutions are less than 30, the average colony count of the lowest dilution multiplied by the dilution multiple shall be reported (see example 5 in the Table). 6.5 If the average colony count of all dilutions is not between 30 ~ 300, meanwhile one dilution is greater than 300, whilst the adjacent dilution is less than 30, THEN, the average colony count close to 30 or 300 multiplied by the dilution multiple shall be reported (see example 6 in the Table). 6.6 If all dilutions show aseptic growth, the reported number shall be less than 10 per gram or per milliliter. 6.7 For the report of colony count, when the colony count is within 10, it shall be reported as the actual value. When it is greater than 100, two significant figures shall ......Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al. Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of English version of GB/T 7918.2-1987 be delivered?Answer: The full copy PDF of English version of GB/T 7918.2-1987 can be downloaded in 9 seconds, and it will also be emailed to you in 9 seconds (double mechanisms to ensure the delivery reliably), with PDF-invoice.Question 2: Can I share the purchased PDF of GB/T 7918.2-1987_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 7918.2-1987_English will be deemed to be sold to your employer/organization who actually paid for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. 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