The Nepal Department of Standards and Metrology has proposed a new standard for rotationally molded polyethylene water tanks. The main feature of the revised standard is the inclusion of a 'migration test'. It tests whether plastic particles are mixed with water from the tank or not.

The microplastic migration test analyzes the amount of micro and nano-sized plastic particles released from the water tank by placing the contents of the water tank in a distilled water food sample at a certain temperature and time.

Anil Shakya, Director of the Nepal Department of Standards and Metrology, said, 'If plastic tanks are not manufactured as per Nepal standards, then when the tanks deteriorate due to prolonged exposure to sunlight and heat, microplastic particles can mix with the stored water.'

He added, 'This revised standard has been prepared to ensure that consumers get safe drinking water and that they are not cheated by low-quality products.'

According to the draft, water tanks for outdoor use should be made of carbon black compounded polyethylene. The amount of carbon black in it should be between 2 and 3 percent and its dispersion should meet the testing process specified under the Nepal Standard.

The standard implemented in 1995 is currently being implemented. Only those who have obtained the Nepal Quality Certificate are following this standard. Those who do not have the quality certificate are not obliged to follow its provisions. Manufacturers who do not have the certificate are allowed to produce and sell tanks without following the standard.

To update the nearly three-decade-old standard, the department has formed a committee comprising representatives of its technical division, engineering campus and water tank manufacturers.

According to the draft, not more than 10 percent of the recyclable material produced during the production of tanks can be used. Similarly, recycled plastic waste or recycled materials from any other source cannot be used in the manufacturing process.

The polyethylene resin used in the construction of water tanks must be of 'rotational molding' grade and stabilized with antioxidants. Similarly, harmful antioxidants cannot be used. Only antioxidants selected from the approved list under Nepal Standards can be used.

According to the proposed standards, the tank should not affect the taste and color of the water. The draft allows manufacturers to produce single-layer or double-layer rotationally molded polyethylene tanks. In the case of double-layer tanks, the inner layer must be white and the outer layer must be black.

'The white inner layer will make it easy for consumers to see whether the stored water is clean or not,' Shakya said.

The revised draft also includes five internationally recognized testing methods. Manufacturers are required to use these methods to ensure the quality and safety of the product.

Manufacturers have welcomed the amendment. They said the previous standard did not ensure state-of-the-art production technology and quality. 'We have been asking the government to revise the standard for a long time and now it is in the final stage,' said Pulkit Jain, director of Hilltech Group.

He said his company has been manufacturing water tanks as per Nepal standards and would support the proposed reform.

'Since most families use water stored in plastic tanks, the government needs to make the quality mandatory,' he said. 'Many consumers are buying poor quality water tanks that do not have Nepal quality certificates.'