This article was authored by Mike Kirschner of Design Chain Associates.
Last week the Öko-Institut opened up a new stakeholder consultation on the three remaining substances proposed for restriction under the RoHS Directive:
- Antimony Trioxide (ATO; a synergist for halogen-based flame retardants);
- Medium-chained chlorinated paraffins (MCCPs) – Alkanes, C14-17, chloro; and
- Tetrabromobisphenol-A (TBBPA)
Öko-Institut’s bottom line and rationale for these three substances is interesting but not unexpected.
ATO: if ATO on its own is restricted, there is a risk of regrettable substitution since – as a consequence of this restriction – an increased amount of halogenated flame retardants is expected to be used, bringing along their predominant negative impacts on health and the environment. In order to avoid this, the consultant proposes not to exclusively restrict ATO, but instead to carry out an assessment of the system of halogenated flame retardants and the ATO synergist with high priority.
MCCPs: Öko-Institut recommends restricting a range of MCCPs, describing that this entry covers chlorinated paraffins containing paraffins with a chain length of C14-17 – linear or branched.
TBBPA: it is recommended to include this substance in the list of restricted substances with a limit value of 0.1 % per weight due to the described risks of TBBP-A and the availability of alternatives. Assuming good and controlled manufacturing conditions, reactive applications and in particular its use as a component of FR4 PWB would not be affected by this restriction, because the residual levels of TBBP-A would be below the proposed limit in this case.
Note that, In light of the upcoming ban of organohalogen flame retardants (OHFRs) in displays/monitors/TVs under the Eco-design Directive, as well as the relatively non-impactful restriction of TBBPA, this should be interesting. In my opinion, in order to effectively restrict ATO, they have to restrict the entire sub-class of OHFRs that ATO would be used with in polymers including PVC and others.
Not to be too overshadowed, another stakeholder consultation is concurrently open on “substance prioritization” for 43 substances that could represent upcoming restriction proposals under RoHS. Öko-Institut is asking for quantitative usage data on these 43 substances.
Both stakeholder consultations are open until January 30, 2020.