TAS GOOD MANUFACTURING PRACTICES FOR SULPHUR DIOXIDE FUMIGATION ON FRESH LONGANS

Transcription

1 THAI AGRICULTURAL STANDARD TAS GOOD MANUFACTURING PRACTICES FOR SULPHUR DIOXIDE FUMIGATION ON FRESH LONGANS National Bureau of Agricultural Commodity and Food Standards Ministry of Agriculture and Cooperatives ICS ISBN XXX-XXX-XXX-XXX-X

2 UNOFFICAL TRANSLATION THAI AGRICULTURAL STANDARD TAS GOOD MANUFACTURING PRACTICES FOR SULPHUR DIOXIDE FUMIGATION ON FRESH LONGANS National Bureau of Agricultural Commodity and Food Standards Ministry of Agriculture and Cooperatives 50 Phaholyothin Road, Ladyao, Chatuchak, Bangkok Telephone (662) Fax (662) Published in the Royal Gazette Vol.127 Section 9D Special, Dated 26 May B.E.2553 (2010)

3 (2) Technical Committee on the Elaboration of Thai Agricultural Standard on Good Manufacturing Practices for Sulphur Dioxide Fumigation on Fresh Longans 1. Mrs. Bussara Chankaewmanee Department of Agriculture 2. Mr. Wijarn Simachaya Pollution Control Department, Ministry of Natural Resources and Environment 3. Mr. Tanongpan Satjapala Department of Medical Sciences, Ministry of Public Health 4. Kalayanee Deprasirtvong Food and Drug Administration, Ministry of Public Health 5. Ms. Nalinthip Peanee National Bureau of Agricultural Commodity and Food Standards 6. Mr. Suwan Hanwiriyaphan Office of Agricultural Research and Development Region 1, Department of Agriculture 7. Mrs. Porntip Visarathanonth Postharvest and Processing Product Research and Development Office, Department of Agriculture 8. Prof. Saichol Ketsa Faculty of Agriculture, Kasetsart University 9. Mr. Somsak Chaimongkol Thailand Institute of Scientific and Technological Research 10. Mr. Amorn Ngammongkolrat National Food Institute 11. Mr. Paiboon Wongchotsathit Thai Fresh Fruit Traders and Exporters Association Chairperson Member Member Member Member Member Member Member Member Member Member 12. Mr. Chaiyapol Kaewprakaisangkul Member 13. Mr.Pongpan Chungyusuk Member 14. Mr. Thiranan Satirapongsasuthi Member 15. Ms. Korwadee Phonkliang Office of Standard Development, National Bureau of Agricultural Commodity and Food Standards Member and Secretary

4 (3) Sulphur dioxide is used as a fruit fumigation treatment to inhibit microbial growth. Many countries set the maximum residue limit of sulphur dioxide for consumer safety. Therefore, the Agricultural Standards Committee deems it necessary to establish an agricultural standard on Good Manufacturing Practices for Sulphur Dioxide Fumigation on Fresh Longans as a guideline for quality of the produce and meeting the maximum residue limit requirement. The standard is based on the information of the following documents: TAS Code of Practice: General Principles of Food Hygiene. National Bureau of Agricultural Commodity and Food Standards Department of Agriculture Certification System for the Plants of Agricultural Commodities in Postharvest and Processing Product Research and Development Bureau Department of Agriculture Production of Off season Longans for Export. Agricultural Product Research and Development Bureau, Region 1 National Food Institute Fumigation Handbook: Dried Longans (with production process and layout), pp 27-28

5 NOTIFICATION OF THE MINISTRY OF AGRICULTURE AND COOPERATIVES SUBJECT: THAI AGRICULTURAL STANDARD: GOOD MANUFACTURING PRACTICES FOR SULPHUR DIOXIDE FUMIGATION ON FRESH LONGANS UNDER THE AGRICULTURAL STANDARDS ACT B.E (2008) Whereas the Agricultural Standards Committee deems it necessary to establish an agricultural standard on Good Manufacturing Practices for Sulphur Dioxide Fumigation on Fresh Longans as a voluntary standard in accordance with the Agricultural Standards Act B.E (2008) to promote such agricultural commodity to meet its standard on quality and safety. By virtue of Section 5, Section 15 and Section 16 of the Agricultural Standards Act B.E. 2551(2008), the Minister of Agriculture and Cooperatives hereby issues this Notification on Establishment of Agricultural Standard: Good Manufacturing Practices for Sulphur Dioxide Fumigation on Fresh Longans (TAS ) as a voluntary standard, details of which are attached herewith. Notified on 11 March B.E (2010) Mr. Theera Wongsamut Minister of Agriculture and Cooperatives

6 TAS THAI AGRICULTURAL STANDARD GOOD MANUFACTURING PRACTICES FOR SULPHUR DIOXIDE FUMIGATION ON FRESH LONGANS 1. SCOPE This agricultural standard establishes good manufacturing practices for sulphur dioxide fumigation on fresh longans starting from the receiving of raw material, processing, storage to transportation so as to obtain produce which is safe and suitable for fresh consumption. 2. DEFINITIONS For the purpose of this standard: 2.1 Establishment means the office, premises, fumigation chamber, gas recapture unit and storage area 2.2 Premises mean the operation areas covering raw material receiving, sorting, packing for fumigation, as well as the area for fumigated produce, area and/or room for storage of fumigated produce prior to transport, storage rooms for packaging materials, chemicals and other supplies. The fumigation chamber and gas recapture unit are not included in such premises. 2.3 Sulphur dioxide means the gas which is obtained from sulphur burning, colourless, and inflammable with strong unpleasant smell. Sulphur dioxide can inhibit microbial growth. 3. REQUIREMENTS AND INSPECTION MOTHODS Requirements and inspection methods are as in Table 1. Table 1 Requirements and Inspection Methods (Section 3) Items Requirements Inspection Methods 1. Establishment 1.1 Location 1.1 The establishment shall be located in the area that has no risk of contamination which affects produce safety and the environment. Preventive measures shall be available Visual inspection of the environment Check the preventive measures

7 TAS Items Requirements Inspection Methods 1.2 Premises, fumigation chamber, gas recapture unit The premises shall have adequate space with area separated for different processes Visual inspection of the premises Design and layout of the premises shall provide good hygienic practices and prevent contamination during the operation which causes adverse effect to the safety of the produce Visual inspection of the layout Internal structures of the premises, fumigation chamber and gas recapture unit shall be strong, easy to clean and maintain Visual inspection of the internal structures The fumigation chamber shall be able to prevent the gas leakage and made of corrosion resistant material. There shall be a glass window and lighting so as to observe the fumigation process Visual inspection of the fumigation chamber The gas recapture unit shall be provided with an effective gas removal system. The system shall be tested Visual inspection of the gas recapture unit Check the test report 1.3 Tools and equipment Availability of sufficient tools and equipment and ready to be used Visual inspection of tools and equipment Tools and equipment shall be easy to clean and maintain Visual inspection of tools and equipment Availability of standardized weighing scale and clock Check the accuracy of the weighing scale and clock

8 3 TAS Items Requirements Inspection Methods 1.4 Safety system and facilities Availability of occupational safety system for operators Visual inspection of the safety system Availability of ready to use gas masks Availability of adequate lighting for the operation Availability of appropriate ventilation in the processing area Availability of adequate drainage and waste disposal facilities which does not cause the risk of contamination to the produce Check the gas masks Visual inspection of adequacy of lighting Visual inspection of suitability of ventilation Visual inspection of the drainage and waste disposal facilities Availability of adequate cleaning facilities Visual inspection of the cleaning tools Availability of adequate personal hygiene facilities and toilets for operators Visual inspection of personal hygiene Chemicals shall be kept in secure storage with clear label in groups Visual inspection of the chemical storage 2. Control of operation 2.1 Raw material Availability of raw material receiving procedure to obtain quality and safe raw material according to the requirements of the establishment Availability of control measure to prevent contamination in handlings of the raw material Check the records of raw material receiving and sorting Visual inspection of the operation

9 TAS Items Requirements Inspection Methods 2.2 Containers 2.2 Containers shall provide adequate protection from damage and contamination. 2.2 Visual inspection of the containers 2.3 Sulphur dioxide fumigation procedure Before the harvesting season, the efficacy of the empty fumigation chamber shall be tested Before the operation, the efficacy of the fumigation chamber with produce shall be tested Availability of preparation check of the fumigation chamber Fumigation operators shall have skill to control the operation correctly The amount of sulphur used shall be controlled so that the maximum residue on the produce does not exceed the limit required by laws and/or the requirement of the trading partners Check the test report on fumigation chamber Check the test report on the produce after fumigation Check the record on the preparation of the fumigation chamber Check training record/on the job training record Visual inspection of the operation and the operation record Check the record on the amount of sulphur used Availability of control system for the uniformity of sulphur dioxide dispersed in the fumigation chamber without leakage Visual inspection of the control system and the operation record Availability of the procedures on the correct and clear operation steps and monitoring Check the procedures 2.4 Operation after fumigation Availability of rapid and effective removal of sulphur dioxide from the fumigation chamber Visual inspection of the operation Check the gas removal record

10 5 TAS Items Requirements Inspection Methods The produce shall be moved out of the fumigation chamber and the remaining sulphur dioxide on the produce shall be removed so that the residue does not exceed the maximum limit required by laws and/or the requirement of the trading partners Visual inspection of the gas ventilation Availability of random sampling of the fumigated produce for analysis of sulphur dioxide Check the result of the analysis of sulphur dioxide 3. Maintenance and sanitation 3.1 Maintenance 3.1 Availability of the maintenance program on the use, checking and repair 3.2 Cleaning 3.2 Availability of cleaning and maintenance of the establishment including tools and equipment 3.1 Check the work program Visual inspection of the establishment and equipment Check the cleaning records 3.3 Disease carrier animal control 3.3 Availability of disease carrier animal control measures to prevent the access of disease carrier animal in the operation area Check the preventive measures Check the record of the control of disease carrier animal 3.4 Waste management 3.4 Availability of the procedure for garbage and waste disposal from the operation area 4. Personal hygiene 4.1 The operators and visitors shall follow the hygienic practices. 4.2 Operators shall perform their duty in a hygienic manner. 3.4 Visual inspection of the operation area 4.1 Visual inspection of the operators 4.2 Visual inspection of the operation

11 TAS Items Requirements Inspection Methods 5. Storage 5. Availability of measures to prevent contamination and deterioration of the produce during storage 6. Transportation 6. Availability of protection of the produce from contamination and deterioration during transportation 5. Check measures to prevent contamination 6. Visual inspection of the protection 7. Record keeping 7.1 The following records shall be available: Test result of the sulphur dioxide removal Receiving and sorting of raw materials, packing and distribution Test result of the efficacy of the empty fumigation chamber and the fumigated produce Preparation check of the fumigation chamber Training /on- the- job training records of the fumigation operators The operations of fumigation The amount of the sulphur used Removal of the remaining sulphur dioxide in the fumigation chamber after use Analysis result of sulphur dioxide on the produce Cleaning and maintenance of tools and equipment Disease carrier animal control 7.2 Records shall be kept for at least 1 year 7.1 Check the records 7.2 Check the record keeping period

12 7 TAS GUIDANCE ON GOOD MANUFACTURING PRACTICES FOR SULPHUR DIOXIDE FUMIGATION ON FRESH LONGANS The recommendations on good manufacturing practices for sulphur dioxide fumigation of fresh longans are intended to be used as a guideline for the fumigation establishment in applying good hygienic practices to obtain safe produce suitable for consumption. Details of the recommendations are given in Appendix A and B.

13 TAS APPENDIX A GUIDANCE ON GOOD MANUFACTURING PRACTICES FOR SULPHUR DIOXIDE FUMIGATION ON FRESH LONGANS (Section 4) A.1 ESTABLISHMENT A.1.1 Location A The location should be kept a distance from the communities which may be disturbed by the emission of sulphur dioxide. The establishment shall have sufficient space and be located in an area where there is no potential source of contamination. If it is unavoidable, measures shall be provided to prevent contamination from disease carrier animal and other contaminants which may have adverse effect on the quality of the produce. Moreover, location of the establishment should comply with the relevant laws and regulations. A The location should not be subject to flooding. The ground should be stable and does not subside, separate or shrink causing the building to crack or collapse easily. A In selection of a location, the area should be spacious enough to separate the operation area from the office, living quarters, parking lot, water treatment pond and other necessities. A The location shall be easy access with sufficient infrastructure. A.1.2 Premises, fumigation chamber and gas recapture unit A Premises A The premises should have adequate space to receive raw material and to store the fumigated produce prior to transportation. The space should be at least 3 times of the existing fumigation chamber. A The internal structure should be made of durable and strong materials with smooth surface, non-toxic, easily cleaned and maintained. The floor should be constructed in order to allow drainage. A The premises and surrounding area should be clean. The floor should be free from water logging and dirt and provided with appropriate drainage system. Garbage and waste shall not be allowed to accumulate in the area. A Space in the premises should be clearly separated, prevented from contamination and convenient for the operation. This includes, for example, areas for raw material receiving, packing, resting of the produce before and after fumigation as well as area and/or room used for storage of the fumigated produce prior to transportation, parking lot for

14 9 TAS vehicles, storage for packaging materials, chemicals and other supplies such as weighing scale, burning trays, labels. A The establishment should be fenced to prevent the entering of pests and disease carrier animals. A Appropriate lighting and ventilation should be provided in the operation area. A Fumigation chamber A A good fumigation chamber shall have a durable and strong structure consisting of a sulphur burner, a ventilation system, the fumigation equipment and a gas recapture unit. The size of the fumigation chamber depends on the amount of the produce to be fumigated. A Walls of the fumigation chamber shall be strong with a smooth surface and free from cracks. The walls shall be made of corrosion resistant material which is non-absorbent of gas. A Door of the fumigation chamber shall be made of the material effectively prevented the leakage of gas such as stainless steel, plywood or formica. A Prevention of leakage at the joints should be undertaken by means of suitable material such as weather strips, silicone or other sealants. A Lighting equipment shall be located in an appropriate position. Its condition should be checked prior to each operation. A A glass window should be provided for observing the gas operation and dispersion. A Sulphur burning can be undertaken by means of an electric or a gas burner installed inside or outside the fumigation chamber. The burner together with its equipment shall be in good condition with effectiveness to completely burn the sulphur. A A glass window should be provided to observe the burn until completed. A The gas recapture unit should be able to effectively remove the gas. It should be of durable structure and free of damage. Components such as air suction duct, extractor fan, water sprayer tower and water tank in which calcium hydroxide is transferable should be identifiable, ready to use and checked at an appropriate interval. A Sulphur dioxide emission into the environment shall be complied with the relevant laws and regulations.

15 TAS A.1.3 Tools and equipment A Tools and equipment should be sufficient for the operation, ready to use and accessed easily. A Tools and equipment should be made of the material which is easy to clean, maintain and check. A The weighing and measuring instrument and clock shall be appropriate for the intended use. The sulphur weighing scale, in particular, should be of accuracy. The weighing scale and clock should be calibrated so as to be accurate at all time. A.1.4 Safety system and facilities A Occupational safety system for operators such as tools, equipment and safety symbols at workplace should be provided. A Gas masks should be adequately provided and ready to use. A Adequate lighting for the operation should be provided. A Appropriate ventilation should be provided in the operation area. A Availability of drainage and waste disposal system and facilities A Appropriate drainage system shall be provided in the premises and the surrounding area. Waste from the operation should not be remained in the drains. A Waste or garbage shall be separated from the operation area. Garbage bin should be sufficiently provided inside the premises. Appropriate waste disposal system should be available. A Adequate cleaning facilities should be provided. Cleaning equipment should be kept separately in an appropriate place. A Personal hygiene facilities and toilets should be adequately provided for the operators. A Toilets should be located outside the operation area or not open directly to the operation area. A Toilets shall be clean, in good and hygienic condition. Wash basins, drying facilities equipped with toiletries shall be provided in front of the toilets. A Chemicals and hazardous substances shall be kept in a secure storage which is clearly labelled and grouped to avoid contamination.

16 11 TAS A.2 CONTROL OF OPERATION A.2.1 Raw material A The raw material shall be sorted by appropriate size and quality. Specification for raw material such as produce condition, wet condition by water or rain, its quality and weight shall be identified. A The raw material should not be placed directly on the floor. The raw material receiving area should be clean and free from water logging and waste. A Data from the random sampling and analysis of pesticide residue of the raw material should be kept. A Raw material should be sampled for its quality and pests to meet the requirements. A.2.2 Containers A The containers shall be clean, made of non-toxic material and can adequately protect the produce from contamination, ready to be used and free from damage. The containers used for toxic or hazardous substances shall not be reused.. A The containers is subject to quality control and should be kept in a clean storage. A.2.3 Sulphur dioxide fumigation procedure A Fumigation shall be controlled by skilled operators who can control the operation correctly. A A proper operation procedure shall be available with clear steps. The operation procedure should contain the following information. A Before fumigation, test the empty fumigation chamber and its equipment such as velocity and air pressure of the blower for the efficiency of the system in controlling the uniformity of sulphur dioxide dispersion as well as the gas leakage. The test result should be recorded as in the Record Form 1 (Check list of the fumigation chamber and the equipment prior to sulphur dioxide fumigation) A Test the fumigation chamber with the produce, the sulphur burner and the internal equipment for the uniformity of the sulphur dioxide dispersion and the gas leakage. A Check the condition of the fumigation chamber such as its cleanliness, weather strips, fan, lighting, burner, exhaust blower, concentration of calcium hydroxide, spraying nozzle, weighing machine and clock.

17 TAS A Demonstrate the schedule showing the amount of sulphur to be used and the fumigation period in relation with the volume of the produce and the storage/transport period A Indicate the arrangement of the produce in the basket, the basket size, placement of baskets in the fumigation chamber and the number of baskets for fumigation A Indicate the sulphur dioxide fumigation such as the amount of sulphur used, the duration in sulphur burning and in fumigation. Record should be kept using the Record Form 2 (the Operation of Sulphur dioxide fumigation). A.2.4 Operation after fumigation A After completed fumigation, the waste gas of sulphur dioxide shall be removed immediately from the fumigation chamber by using gas recapture unit. A The fumigated produce shall be moved out of the fumigation chamber and the leftover of sulphur dioxide on the produce shall be blown so that the residue does not exceed the limit required by laws or the trading partners. A The fumigated produce shall be kept under an appropriate condition to prevent recontamination. A Random sample should be drawn from the fumigated produce for analysis of sulphur dioxide. A.3 MAINTENANCE AND SANITATION A.3.1 Maintenance A The maintenance programme on the use, checking, repair and maintenance of the machinery and equipment should be available. A Tools, equipment and machinery associated with the operation shall be checked and maintained to function effectively. A.3.2 Cleaning A Premises and fumigation chamber Clean, maintain and repair of the floor, walls, ceiling and fixtures on the walls or ceiling of the premises as well as regularly check leakage in the joints of the fumigation chamber. Cleaning programme should comprise of methods and frequency including responsible persons. A Tools and machinery and gas recapture unit and equipment shall be cleaned and maintained to function effectively. Cleaned tools and equipment should be kept separately in an appropriate place.

18 13 TAS A.3.3 Disease carrier animal control A Good hygienic practices shall be employed to avoid favourable environment for pest and disease carrier animal infestation. The internal and external area, for example, should be kept clean. Waste should be discarded in a pest-proof bin. A Measures to prevent the entering of pests and disease carrier animal in the operation area should be available. The repair of the premises is needed to prevent the access of disease carrier animal and to eliminate potential harbouring and breeding sites. Holes, drains and other places where disease carrier animal are likely to gain access should be kept sealed with, for example, mesh screens. A Treatment with chemicals, biological agents or physical methods should be carried out without compromising the safety of the produce. Using of pesticide in the operation area shall take into account the risk of contamination on the produce. A.3.4 Waste management A Appropriate drainage in the premises and the surrounding area and waste management should be provided. Waste from the operation shall not be remained in the drains. A Waste or garbage shall be separated from the operation area. Garbage bins should be adequately provided inside the premises with an appropriate garbage disposal management. A Garbage bins for waste and chemicals should be kept separately and clearly labelled to prevent contamination on the produce. A.4 PERSONAL HYGIENE A.4.1 Personal hygiene of the operators should be checked to minimize the chance of contamination to the produce. Record of personal hygiene should be kept for regular inspection as follows: A Operators shall have good health and not be a disease carrier. A Appropriate clothing should be worn for the assigned duties, particularly for the fumigation operators. A Operators shall perform their duty in a hygienic manner by, for example, refraining from smoking, spitting or use of chewing gum while on duty to avoid contaminating the produce.

19 TAS A.5 STORAGE Produce prior to transportation shall be kept under appropriate condition with measures to prevent contamination and deterioration during storage. The produce should be kept orderly for convenience of moving. Appropriate temperature control should be provided as well. A.6 TRANSPORTATION A.6.1 Shipping containers should be temperature controlled, cleaned, ready to use and under appropriate condition. A.6.2 Transportation should be undertaken in such a manner that the produce is protected from damage. Measures should be available to protect the produce from contamination from pest, disease carrier animal or dirt during transportation. A.7 RECORD KEEPING A.7.1 The complete records of the operation processes should be kept including testing result of the sulphur dioxide removal, receiving and sorting of the raw material, packing and distribution, test result of the efficacy of the empty fumigation chamber and the fumigated produce, preparation check of the fumigation chamber, training/on- the- job training records of the fumigation operators, the operations of fumigation, the amount of sulphur used, removal of the remaining sulphur dioxide in the fumigation chamber after use, analysis result of sulphur dioxide on the produce, cleaning and maintenance of tools and equipment, disease carrier animal control and other useful records for the purpose of traceability. A.7.2 Records shall be kept by using the Record Form 1 (Check list of the fumigation chamber and the equipment prior to sulphur dioxide fumigation) and the Record Form 2 (the Operation of Sulphur dioxide fumigation). These records should be signed by the responsible person/the supervisor. A.7.3 Records should be kept orderly, accessed easily and retained for at least 1 year.

20 15 TAS Example Record Form 1 Check list of the fumigation chamber and the equipment prior to sulphur dioxide fumigation (A.2.3 and A.7 of Appendix A) Name of establishment Certification code Date Fumigation chamber No. Cleanliness Weather strips Fan Lighting Burner Exhaust blower Concentration of calcium hydroxide Spraying nozzle Weighing scale Clock Recorder Remark: Check in the column where appropriate (Signature).Inspector/Supervisor

21 TAS Example of Record Form 2 The Operation of Sulphur dioxide fumigation (A.2.3, A.2.4 and A.7 of Appendix A) Name of establishment Certification code Date Lot No. Fumigation chamber No. Number of baskets Produce weight (kg) per basket Condition of the longans prior to fumigation Normal Other (specify) Weight of sulphur (kg) Fumigation time Gas removal time End of the process time Recorder (Signature). Fumigation operator /Supervisor

22 17 TAS Example of Record Form 3 Training record (A.2.3 and A.7 of Appendix A) Name (Mr/Mrs/Ms) Family name.age.years Academic qualification Start working date Title/Topic of training Date of training Duration of training Training organization/ venue Evaluator (Signature) Recorder

23 TAS APPENDIX B EXAMPLE OF THE USE OF SULPHUR IN FUMIGATION ON FRESH LONGANS B.1 Recommended amount of sulphur used in fumigation Dimension of the fumigation chamber (length x width x height) (m) Volume of the fumigation chamber (m 3 ) 3.6 x 2.4 x x 2.4 x x 3.6 x x 4.8 x Number of baskets (10 kg per basket) Amount of sulphur to be used (kg) Source: Production of Off season Longans for Export, Department of Agriculture (2008) Note: 1. This data is obtained from the study on the fumigation of longans of Edo species of which the sulphur dioxide residue on the fruit does not exceed 50 mg/kg. 2. The amount of sulphur used may vary 10% - 20% where appropriate 3. The requirements on sulphur dioxide residue specified in the relevant laws and regulations and/or requirements of the trading partner should be taken into account.

24 19 TAS B.2 Formula for calculation of the amount of sulphur to be used B.2.1 Calculation of basic dosage Calculation of the basic dosage depends on the desired maximum residue level (MRL) of sulphur dioxide (SO 2 ) which is subject to the storage, transport duration and the requirements of the trading partner. Some countries, for example, allow the maximum residue level of 350 mg/kg on the whole fruit basis. The other factor is the amount of the SO 2 remainied in the fumigation chamber after completion of the operation. The basic dosage is calculated by the following formula: Weight of SO 2 (g) = M+S Where = (W A) (C F D) M= MRL (Maximum residue level of SO 2 on the whole fruit basis after completion of the operation, in g) S= Space dosage (Concentration of SO 2 remained in the fumigation chamber after completion of the operation) W= Weight of fruit (Weight of longans to be fumigated, in kg) A= Absorption of fruit (SO 2 absorption of longans, in g/kg) C= Concentration of SO 2 to maintain (Concentration of SO 2 in the fumigation chamber after completion of the operation, in percentage) F= Free space in the room (Free space after reduction of the longan volume in the fumigation chamber in L) D= Density of SO 2 At the average room temperature of 25 C, D= g/l At the average room temperature of 27 C, D= g/l At the average room temperature of 30 C, D=2.575 g/l Weight of sulphur to be used = Weight of SO 2 (in g)/2 B.2.2 Ratio of the fumigation chamber and the weight of fruit To provide adequate space for the dispersion and distribution of sulphur dioxide, the recommended ratio of the fumigation chamber (in m 3 ) and weight of longans to be fumigated (in tonne) is from 10:1 to 15:1.

25 TAS B.2.3 Correction factor Correction factor is the increase of the amount of sulphur from 10% to 20% depending on the component of the fumigation chamber, absorption of the walls, absorption of the longan stalks, packaging materials, leakage of the gas through the holes and door of the fumigation chamber as well as the purity of the sulphur used. The correction factor can be obtained by conducting fumigation test and determine the maximum residue level of sulphur dioxide on the fruit after the fumigation is completed. B.2.4 Fumigation duration After the complete burning of sulphur to sulphur dioxide and the final concentration of sulphur dioxide in the fumigation chamber is 1.5% or 15,000 mg/kg or when the smoke becomes thin enough to see inside the fumigation chamber, the fumigation time shall be minutes to be considered as completed operation. The inside gas can be blown out to the gas recapture unit. The fumigation duration, however, depends on the concentration of sulphur dioxide and the sulphur dioxide residue.

26 21 TAS APPENDIX C UNITS The units and symbols used in this standard and the units recognized by the International System of units (Le Système International d Unités) or SI are as follows: Quantity Unit Symbol Length, width, height metre m milligram mg Mass gram kilogram g kg tonne t Volume cubic metre m 3 litre L Temperature Degree Celsius C