ISO 35:2004 specifies a method for the determination of the mechanical stability of natural rubber latex concentrate. It is also applicable to prevulcanized natural rubber latex concentrate.

The method is not necessarily suitable for latices or prevulcanized latex preserved with potassium hydroxide, latices from natural sources other than Hevea brasiliensis, or for compounded latex or artificial dispersions of rubber, and it is not applicable to synthetic rubber latices.