LS/T 1223-2020Technical specification for storage of emergency reserve milled rice (English PDF)

4.1 Basic requirements

4.1.1 Necessary finished grain storage facilities are provided to ensure the quality of rice entering the warehouse and the integrity of rice packaging, and reasonable technical measures are adopted to reduce losses and damage, prevent pollution, and delay quality decline.

4.1.2 Before the grain is stored, the granary and storage yard shall be cleaned to remove any remaining rice grains, ash, and debris, and any gaps shall be sealed. If pests are present, they shall be killed with pesticides, and the warehouse shall be cleaned before the grain is stored. For floors that cannot be insulated from moisture, moisture-proof materials shall be laid down before the grain is stored.

4.1.3 The safety of emergency rice storage shall be ensured. Storage technical requirements shall be implemented in accordance with GB/T 29890.

4.2 Requirements for rice entering the warehouse

4.2.1 Emergency storage of milled rice entering the warehouse shall meet the quality requirements specified in GB/T 1354 and GB/T 5502 and have a milling degree of grade

II or above; it shall also meet the relevant food safety standards.

4.2.2 Rice of different grades, moisture contents, varieties, and production years shall be stored separately. For rice intended for long-term storage, the moisture content shall be below 13.5%. Low-temperature storage can control the moisture content of rice to around 14.5%.

4.2.3 Rice grains with a temperature difference of more than 5 °C shall be stored in separate stacks.

4.3 Requirements for warehouse construction

4.3.1 Emergency storage of milled rice shall be stored at low or quasi-low temperatures, using horizontal warehouses or multi-floor warehouses with good moisture-proof, heat- insulating, and thermal insulation properties. The basic construction of the warehouses shall comply with the provisions of Building Standard 172 and GB 50320, meeting the requirements for moisture-proof, waterproof, airtight, thermal insulation, ventilation, and prevention of harmful organisms in the stored grain. Furthermore, the outer surfaces of the warehouse covers and walls shall be light-colored or made of materials with high reflectivity.

4.3.2 The warehouse shall be equipped with temperature control systems and devices such as air conditioning and mechanical ventilation. In areas with high humidity, dehumidification devices shall also be provided.

4.3.3 The construction of warehouses shall comply with the design requirements of

Exhibition Document No. 37 [2012] of the National Grain Office.

4.4 Packaging requirements

4.4.1 Packaging shall be wear-resistant and have a certain load-bearing capacity, and comply with the provisions of GB/T 8946.It is recommended to use single-sided breathable plastic woven sacks with a size of 25 kg or 50 kg.

4.4.2 The packaging sack shall clearly indicate the rice's production date, variety, net weight, and manufacturer, and the production date of the rice entering the warehouse shall be within one month prior to the date of entry into the warehouse.

4.5 Stacking requirements

4.5.1 Different stacking methods shall be adopted according to different packaging specifications. 25-kg packaging shall be stacked in multiple layers on pallets, with a single pallet load of 1 t; the height of rice stacked on the pallet shall not exceed 1 m, the number of stacked layers shall not exceed 3 layers, and the bottom pallet shall be

0.3 m off the ground; 50-kg packaging shall be naturally stacked in multiple layers.

4.5.2 Stacking forms are divided into solid stacks and ventilated stacks based on the moisture content of the rice. Aisles shall be left between stacks, with main aisles being wider than 2.0 m and side aisles being at least 0.6 m wide. Stacks shall be at least 0.5 m away from walls. Stacks shall be neat, secure, and not tilted, and shall avoid being stacked around pillars or against walls.

4.6 Temperature and humidity requirements

The temperature and humidity of the granary shall be adjusted to keep the temperature below 20 °C and the humidity at 65%±5%; it shall be ensured that the emergency storage of milled rice can be safely stored through the summer.

4.7 Requirements for tempering rooms

4.7.1 A tempering room shall be set up for the tempering of in-and-out storehouse. The tempering room shall be a small horizontal warehouse or a multi-floor warehouse. The size shall be matched with the size of the storage warehouse, and it is advisable to set it at 10%~20% of the size of the storage warehouse.

4.7.2 The tempering room shall be constructed close to the storage warehouse, away from pollution and hazardous sources, avoiding low-lying and flood-prone areas, and facilitating operations of in-and-out warehouse. The building structure shall meet the requirements of GB 50320.

4.7.3 The ground shall be flat, intact, and firm, and equipped with a moisture-proof layer. The inner walls shall be intact, flat, and equipped with a moisture-proof layer.

The walls shall be free of cracks, and the joints between the walls and the warehouse floor, adjacent walls, and the ground shall be tight and seamless.

4.7.4 The roof of the warehouse shall be intact, with a heat insulation layer and a waterproof layer, and the suspended ceiling shall be made of heat insulation material.

4.7.5 The housetop and exterior of the warehouse shall be light-colored or made of materials with a high color reflectivity.

4.7.6 Doors, windows, and ventilation openings shall be airtight and heat-insulated.

Insect-proof wires, insect-proof boards, and nets shall be installed at doors, windows, and openings to prevent insects, rodents, and birds.

4.7.7 Lighting fixtures shall comply with the provisions of GB 50320.

5.1 Temperature and humidity control of the storage environment

5.1.1 Storage temperature control

The storage temperature control requirements are as follows.

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