Corporate Research & Development Center

Toshiba Develops's Simple, Low-Cost Testing Method for Phthalate Esters
-Highly Accurate Screening to Detect RoHS Newly Added Substance-

7 Jun. 2018
Toshiba Corporation


Toshiba has developed a simple, low-cost testing method for the phthalate esters that are being added to the European Restriction of Hazardous Substances Directive (RoHS). The new technique uses simple equipment and procedures to keep testing costs low, but nonetheless achieves high separation and accuracy that allows restricted substances to be distinguished from other substances. Details of the method will be presented on 22 May at the Symposium on Environmental Chemistry, in Okinawa, Japan.

Development Background

In July 2019, four phthalate esters will be added to the restricted substances covered by the RoHS, the regulation covering use of chemical substances in the EU, and the model for many countries around the world. Because of this, building systems for managing phthalate esters has become a pressing issue for many companies. If it is not possible to determine the presence or absence of phthalate esters in procured materials, confirmation testing is needed. However, the current testing method requires advanced analysis equipment, and testing incurs large costs for installation, transportation, and maintenance, as well as securing personnel with advanced technical skills. Cost concerns have raised demand for a simpler, cheaper testing method, but existing methods of simple analysis cannot separate restricted phthalate esters from other isomeric substances that are the most widely substitute plasticizers.

Features of This Technology

Toshiba's newly developed testing method detects restricted phthalate esters present in products at or above the RoHS directive threshold (0.1 wt%), and does so simply and at low cost. Separation and detection is achieved by extracting an organic solvent that can by analyzed by thin-film chromatography(Note 1).

Testing was simplified by identifying conditions under which the target phthalate esters can be extracted without dissolving the host material, using a very low volume of organic solvent, 0.5ml or less, in the extraction procedure. This eliminates the need to separate the host material from the extracted liquid and to concentrate the extracted liquid, a requirement under the current method. For the thin-film chromatography method, Toshiba has developed test conditions that achieves simultaneous separation of restricted phthalate esters, other phthalate esters, and substitute plasticizers in only 10 minutes, for 10 samples at once. This is the usual of samples tested at one go in chromatography, but Toshiba's system can test even more samples in a batch, by using more chromatography plates. Importantly, this approach can be applied to polyvinylchloride and rubber, where the presence of phthalate esters is highly possible. In terms of cost, installing the equipment required for this technique is inexpensive, at around 200,000 JPY, against an installation cost of over 10 million yen for instrument-based analysis. This immense differential greatly reduces testing costs.

Future Development

Toshiba will use the new phthalate ester testing method widely within Toshiba Group.

(Note 1)
In chromatography, spots of an extracted liquid, which contains multiple substances, are dripped onto a substrate with a thin coating, such as silica gel, aluminum or polyamide resin, that is then immersed into an appropriate solvent to separate the component substances.