Phthalates are chemical plasticizers, commonly used to soften plastics and make them more pliable. Over the past decade, numerous phthalates have come under scrutiny for their potential harmful effects on human health, especially the reproductive system, resulting in the bans of many phthalates. Various techniques can be used to test phthalates, such as GC/MS and LC/MS, and using chemical ionization in the testing techniques has proven to ensure extremely accurate results. Companies like Hitachi High-Technologies have developed instruments incorporating chemical ionization that are designed for phthalate testing, as firms around the globe prepare for the changing regulations on phthalates that affect a huge portion of the production of consumer goods.
In 2015, as per the Registration, Evaluation, Authorization and Restriction of Chemicals regulation in Europe, the EU announced a ban on the use of four phthalates: butylbenzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP) and diisobutyl phthalate (DIBP). These phthalates are used in numerous consumer products, such as toys, coated fabrics, flooring, cosmetics, shampoo, mattresses and footwear. As per the 2015 ruling, companies were still able to receive continued-use authorizations if they could prove that they had no other safer substitutes for the phthalates.
However, earlier this year, the European Commission made a final ruling that identified the four phthalates as toxic to human health, which is likely abolish the option for continued-use authorizations for products containing the phthalates in question in quantities greater than 0.1% (by weight). The ban is to be implemented in summer 2019.
In Europe, the first step in banning a substance is its addition to the Candidate List of the European Chemical Agency (ECHA), and after undergoing review by the Member State Committee (MSC) of the ECHA, it is placed on the Authorization List. “However, even if a substance is eventually included in the Authorization List, this does not mean that the substance is banned,” an ECHA spokesperson said. “The use can continue after the sunset date [the date from which the placing on the market and use of a substance is prohibited, unless an authorization is granted], provided a use-specific and applicant-specific authorization is applied for and granted. The authorization process does not trigger any further testing requirements.”
In 2008 and 2010, the MSC unanimously agreed that the four phthalates (BBP, DEHP, DBP and DIBP) be added to the Candidate List. As the ECHA told IBO, the phthalates were later listed in the Authorization List due to their reprotoxicity, as they have harmful effects to the human endocrine system. In 2014, after reviewing additional proposals on the four phthalates, the MSC deliberated classifying them as Substances of Very High Concern (SVHC). “While the MSC did unanimously agree on the endocrine disrupting properties of DEHP with effects on the environment, they were not able to unanimously agree on the four proposals with respect to their endocrine disrupting properties affecting human health,” said the ECHA. “As a result, MSC opinions on each of the four cases were sent to the European Commission for final decision making.”
In summer 2017, the European Commission made a final ruling that BBP, DEHP, DBP and DIBP indeed had endocrine-disrupting properties, resulting in the phthalates being officially classified as SVHCs. The ban will be implemented beginning July 22, 2019, for all electrical and electronic equipment, excluding medical devices, and monitoring and control equipment. Companies will have an additional two years (until July 22, 2021) to comply.
The ECHA has not recommended a specific technique for testing phthalates, as the possibilities are numerous—MS, GC/MS, LC/MS, GC/MS/MS, LC/MS/MS, GC-FID are some of the more frequently used techniques for phthalate testing due to their sensitivity as GC/MS can detect down to 50 ppb of the phthalates and LC/MS can detect down to 1 ppb.
According to the spokesperson from the ECHA, generally, GC-FID methods are commonly used for quantification, although they are required to be used in accordance with standards. “MS methods are commonly used for identification purposes—for quantification purposes, they are usually coupled with other specific techniques,” the ECHA further explained.
As the ECHA told IBO, researchers first must determine what conditions the testing and analysis require. “The choice of an appropriate technique may depend on the amount of analyte expected to be present in a substance/mixture/article,” he said. “Analyzing very low concentration levels of analytes may require the use of specific techniques or the development of suitable analytical methods. When choosing an analytical procedure, it should also be considered that different matrices may require the use of different extraction techniques.”
“Demand has grown for screening instruments that allow easy phthalates detection because such instruments can be useful from upstream to downstream business.”
As there are many techniques to conduct phthalate testing, the ECHA suggests using the most appropriate technique according to the circumstances under which analysis is to be performed. “Analyses can be carried out on the basis of the available known techniques, including standard methods and taking into account that analytical techniques are in continuous development,” he stated.
Many companies sell LC/MS or GC/MS systems for phthalate testing, such as Agilent Technologies, which incorporates the techniques for phthalate testing in food, and Shimadzu’s Py-Screener, which is designed to screen phthalate esters in polymers through pyrolyzer GC/MS. Thermo Fisher Scientific developed a method using FT-IR spectroscopy, while XOS sells the HD Prime, an instrument with analytical techniques in accordance to ASTM standards that uses high-definition XRF for phthalate testing.
Of the systems Hitachi High-Technologies sells for phthalate testing, the HM1000 thermal desorption MS shows the highest demand, as the instrument is specifically designed for screening phthalates. As Yu Nakamura, engineer for the International Sales and Marketing Department at Hitachi told IBO, instruments such as the HM1000 offer various functionalities that can target customers throughout the supply chain. “Demand has grown for screening instruments that allow easy phthalates detection because such instruments can be useful from upstream to downstream business,” he said.
The HM1000 uses Atmospheric Pressure Chemical Ionization (APCI), to increase the sensitivity and selectivity of the ionization process. “Using this ionization method, soft ionization is possible without destroying the phthalate ester structure,” Mr. Nakamura explained. “In other words, mass analysis on the original structure becomes possible, and it is possible to inspect the phthalate without GC.”
Using APCI as opposed to GC lowers operational costs, as an APCI-based instrument does not require expensive helium gas and separation columns. It also produces higher throughput, according to Mr. Nakamura. “Conventional methods like GC/MS have a number of drawbacks when it comes to [use] on the factory floor,” he said. “The HM1000 requires only 10 minutes to measure the phthalate content per sample, while GC/MS needs approximately 60 minutes.”
According to the ECHA, single quadrupole MS and triple quadrupole MS are used for testing phthalates depending on the intricacy of the matrices. “Single quadrupole mass spectrometers are commonly chosen for identification and quantification purposes in relatively simple matrices,” he explained. “Triple quadrupole mass spectrometers allow high selectivity and lower detection limits, especially in complex matrices.”
Hitachi’s HM1000, however, takes advantage of the APCI function to tests the sample with greater precision, so that triple quadrupole MS becomes less necessary for various types of matrices. Using single quadrupole MS, the HM1000 directly heats the sample to vaporize the phthalates from it, and the precision of the sample’s temperature conditions ensures that the vaporizing process does not damage the sample, thus eliminating the need for triple quadrupole MS in many cases. “By precisely controlling the sample heating temperature, only the phthalate ester is vaporized without decomposing the main component,” Mr. Nakamura said.
As there are still 2 years before the EU’s ban on 4 additional phthalates is implemented, Hitachi has not yet seen an increase in sales for the HM1000 for phthalate testing. Like many other firms, Hitachi is “assessing the situation,” as Mr. Nakamura stated, waiting to see what moves other companies make. “Historically, sales leads start to increase a year before such a regulation goes in effect,” he explained. “It takes time to build the structure [for] how to manage the phthalates and, therefore, many companies (typically major corporations and end-product manufacturers) start to introduce a testing system a year earlier. So we expect that the sales leads be in a full scale.”
Hitachi expects that sales for the HM1000 will increase with the EU ban going into effect, especially since the HM1000 is used for first screening purposes. As Mr. Nakamura explained, the market is focusing on environmental concerns, which is likely to positively influence the sales of phthalate testing instruments. Moreover, there may be a “ripple effect,” as he put it, on the phthalate testing process that may affect sales. “It is often the case that leading companies will build the structure on how to manage the phthalates (e.g., first screening by the HM1000, second screening by GC/MS for the items that were 700 ppm or more by the first screening),” he said. “Then they tend to request their suppliers to adopt the same way.”
Another factor predicted to increase the sales of phthalate testing instruments in relation to the regulation is the multitude of products that can be tested with the instruments, which subsequently increases sales volume. “There are so many items you may possibly test under the regulation, and that could give an incentive to improve efficiency in operation while minimizing costs,” said Mr. Nakamura.
Whether an APCI-based instrument like Hitachi’s HM1000 becomes an industry standard and replaces techniques like GC/MS is yet to be seen, but instrument companies like Hitachi are working to develop the proper resources and methods required to prepare for the likely increase in sales for phthalate testing instruments. As Mr. Nakamura stated, “The challenge we have is that we really need to structure a robust service infrastructure before the restriction goes into effect.”