Warning: Personnel using this standard should be familiar with regular laboratory operating procedures. This standard is not intended to address all safety issues that may arise from the use of this standard. Users should formulate corresponding safety and health rules and ensure compliance with relevant national regulations. This standard specifies the method for determining the viscosity of natural latex using an L-type rotational viscometer. This standard is applicable to the determination of the viscosity of natural latex, and also to the determination of the apparent viscosity of special latex prepared from natural latex.