Waste management of electrical and electronic equipment

• Author: Clemm, Christan; Löw, Clara; Baron, Yifaat; Moch, Katja; Möller, Martin; Köhler, Andreas R; Gensch, Carl-Otto; Deubzer, Otmar
• Pages: 28-37

RoHS Annex II Dossier, final

TBBP-A (flame retardant)

28

5. WASTE MANAGEMENT OF ELECTRICAL AND ELECTRONIC EQUIPMENT

5.1. Description of waste streams

According to BSEF, TBBP-A is produced mainly in Israel, the United States, Jordan, Japan and PR

China.72 Thus, releases of the substance from primary production processes are not expected to

occur in Europe. Certain amounts of TBBP-A are imported as a commoditised intermediate chemical

(see 2.3), which is used for the manufacturing of various EEE products. Notably, TBBP-A is used as

a reactant in the manufacturing of FR4 printed wiring boards (PWB). However, wastes emerging

during the PWB production do not fall under the scope of the RoHS directive.

RoHS relevant waste encompasses post-consumer WEEE, which contains TBBP-A mainly in form

of an additive flame retardant in plastic components (such as ABS-parts). Reacted TBBP-A occurs

in rigid FR4 PWB but does no longer exist in its original substance identity (see 2.2). Hence, TBBP-

A cannot be analytically identified in PWB fractions of WEEE except for unreacted TBBP-A from the

original PWB production. TBBP-A detected otherwise in WEEE cannot be attributed to the PWB.

It must be noted, that the literature does not always clearly distinguish the difference between

reacted and not reacted TBBP-A in WEEE. Moreover, accounts on the TBBP-A contents, found in

WEEE categories are at odds with the figures on TBBP-A used, reported in section 2.3.

Taverna et al. (2017)73 for instance, examine typical EEE flame retardants as part of the material

flows in the Swiss WEEE treatment system. In this study, 220 tons of WEEE with a typical

composition with regard to the WEEE categories74 was examined based on the statistical WEEE

composition of Switzerland in the year 2009. This study found that, out of the 18 flame retardants

examined, TBBP-A was the most abundant one with a mean concentration of > 600 mg/kg waste in

composite samples from all output streams of WEEE processing. With focus on TBBP-A, the

following three output streams (out of 13 examined in total) are important:

- PWBs (representing 2 % of the total WEEE output mass flow),

- polymer components from dismantled EEE housings (5 % of the total WEEE output mass flow),

- polymer particle fraction generated by shredding of WEEE (23 % of the total output mass flow).

In these three outputs, TBBP-A was always found to be the most abundant flame retardant. For the

PWB output stream, TBBP-A was found with an average concentration of 390 mg/kg by far more

than from other FR (next followed by DecaBDE with 110 mg/kg). In computer and notebook housings

made form polymeric material, TBBP-A was present with 4,000 mg/kg (next followed by DBDPE with

1,400 mg/kg); and finally, an average concentration of 1,700 mg/kg was detected in the polymer

particle fraction with diameters < 25 mm (next followed by DBDPE 1,100 mg/kg).

From the distribution of TBBP-A in the examined output streams it can be concluded that > 90 % of

additively applied TBBP-A content in WEEE ends up in the polymer fraction (housings + polymer

particles) as can be seen from Figure 5-1. The PWB output stream holds a share of only 1 % of the

TBBP-A. This result proves the assumption that the release of unreacted TBBP-A from poly epoxy

72 BSEF, Fact sheet TBBP-A: Tetrabromobisphenol A for Printed Circuit Boardsand ABS plastics. 2007: Brussels,

Belgium

73 Taverna, R. et al. (2017): Stoffflüsse im Schweizer Elektronikschrott. Metalle, Nichtmetalle, Flammschutzmittel und

polychlorierte Biphenyle in elektrischen und elektronischen Kleingeräten. Bundesamt für Umwelt, Bern. Umwelt-

Zustand Nr.1717

74 Based on Taverna (2017): Figure 5, pg. 30, the investigated composition included: 25% IT equipment without monitors;

1% laptops; 3% LCD monitors; 9% CRT monitors; 3% communications equipment; 7% mixed consumer electronics

without TVs; 9% LCD TVs; 14% CRT TVs; and 27% small household applianc es.