REACH Concentration Calculations (W/W)


How should weight by weight (w/w) concentrations be calculated to ensure compliance under the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) Regulation?


To understand how w/w concentrations are calculated, you first need to understand the definition of an article under the REACH Regulation. For example, if the product in question is a cell phone case, it is likely made of two pieces: a hard shell to protect against scratches and a soft interior piece to absorb impact. Even before the two pieces are put together to form the case, they are more than substances or materials. The form and design of the pieces define their use, so under the REACH Regulation, each piece is considered an article. The w/w calculation must be performed for every article in an object.

Imagine the hard shell of the phone case contains a Substance of Very High Concern (SVHC) in its pigment, such as Bis(2-ethylhexyl) phthalate. To calculate the w/w concentration, divide the weight of the phthalate used in the hard shell by the full weight of the hard shell. If the resulting percentage is greater than 0.1, the company that produced, imported or sells this article by itself or combined with other articles (i.e. complex object) would be required to communicate the presence of the phthalate to customers so safe-use information can be identified.

See also: What is an "Article" under REACH?, REACH Concentration Calculations for Adhesives 

Article is current as of 2019-11-22.

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