Exposure estimation during use and/or during weee treatment

• Author: Clemm, Christan; Löw, Clara; Baron, Yifaat; Moch, Katja; Möller, Martin; Köhler, Andreas R; Gensch, Carl-Otto; Deubzer, Otmar
• Pages: 31-33

RoHS Annex II Dossier, final

Indium phosphide

31

7 EXPOSURE ESTIMATION DURING USE AND/OR DURING WEEE TREATMENT

7.1 Basis of exposure estimation

According to the available figures for the different application fields, the total volume of indium

phosphide placed on the European market through InP applications is estimated to be ~ 100 kg

p.a. It is understood that this amount includes both applications produced within the EU as well as

imported amounts of InP (see section 3.3 for more details).

In the light of its physico-chemical properties, indium phosphide is not considered to be volatile.

Furthermore, based on the available information, it is not applied as a surface material, but

encapsulated in wafers and quantum dots. Even though specific information regarding release rates

are not available, the potential for emissions during the use of the substance appears to be very

limited (see section 3.4).

7.2 Human exposure estimation

7.2.1 Exposure of workers

7.2.1.1.1 Workers in the production of InP containing EEE

Nanosys refers in its contribution to the 2nd stakeholder consultation to the exposure of workers in

quantum dot manufacturing. The company explains that InP would not be an input to the InP/ZnS

QD manufacturing process. Furthermore, manufacturing InP/ZnS quantum dots would not involve

transporting quantities of pre-made InP through communities where there may be some risk of

spillage. In the InP QD manufacturing process the InP cores would be made and encapsulated in a

shell in situ before it is ultimately incorporated into a film or device.83

In the IARC monograph on InP 84, some exposure data is presented for workers in the semiconductor

and microelectronics industry “where workers are involved in the production of indium phosphide

crystals, ingots and wafers, in grinding and sawing operations, in device fabrication and in clean-up

activities.”

7.2.1.1.2 Workers of EEE waste processing plants

In this dossier, only the possible exposure of humans related to the handling, treatment and disposal

of WEEE with contents of InP is addressed. Against this background, waste from three different

product types is considered:

• Waste from use in printed wiring boards of optoelectronic and high-speed electronic applications;

• Waste from display screens containing InP QDs, and

• Waste from lighting equipment containing InP QDs.

As appears from section 6.1, the total amount of InP available for potential exposure of humans in

the WEEE phase are small, in the worst case a maximum of 100 kg p.a. for the applications

mentioned above. Printed wiring boards of optoelectronic and high-speed electronic

applications contain various rare and precious metals that to a large extent can be recovered at the

83 Op. cit. Nanosys (2019)

84 See footnote 61