The RoHS (Restriction of Use of Restricted Substances) regulation limits the concentrations of certain hazardous substances used in the manufacture of electrical and electronic equipment (EEE). In 2015, the RoHS 2 regulation was updated with the addition of four phthalates (chemical compounds known as emollients) to the list of restrictions. These phthalates are:

1. Bis(2-ethylhexyl) phthalate (DEHP)
2. Butyl benzyl phthalate (BBP)
3. Dibutyl phthalate (DBP)
4. Diisobutyl phthalate (DIBP)

From 2019, these substances are restricted to a limit of 0.1% by weight (i.e. 1000 ppm) per homogeneous material in newly introduced EEE products.

The main methods used for the determination of phthalates are:

1. **GC-MS (Gas Chromatography-Mass Spectrometer)**: It is a widely used method for the detection of phthalates. GC-MS provides separation and specific detection of phthalates.

2. **LC-MS/MS (Liquid Chromatography-Tandem Ash Spectrometer)**: Used for phthalate detection in some cases, especially in water-based matrices.

3. **FTIR (Fourier Transform Infrared Spectroscopy)**: This method can be used to qualitatively detect the presence of phthalates in plastic matrices, but is often used in combination with another method for quantitative analysis.

To ensure RoHS compliance, manufacturers and importers must certify that materials and ingredients used throughout the supply chain do not contain these phthalates or are below allowable limits. This must be taken into account both during the product design and development phase and during the manufacturing process. It is also recommended to carry out periodic tests on products when in doubt.