Skip to main content

Product characteristics and tariff classification

CN code 390799 covers polyesters in primary forms not classified under codes 390710-390791. This is a residual heading covering a broad range of engineering and speciality polyesters, such as polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), liquid crystal polyesters (LCP), polybutylene succinate (PBS) and other saturated and thermoplastic polyesters. PBT is one of the most important polyesters in this group, used as an engineering polymer in producing electrical components, connectors, housings and automotive parts. PTT is used in carpet fibre production with excellent resilience. Products come as granules or powder. Classification requires precise polymer identification and exclusion of more specific subheadings.

Regulatory requirements for import

Polyesters imported under code 390799 are subject to REACH regarding monomers and additive substances. PBT and PTT are polymers exempt from REACH registration, but their monomers (terephthalic acid, butanediol, propanediol) are subject to regulation. PBT used in electrical equipment is subject to the RoHS Directive – particularly relevant is the restriction on brominated flame retardants in glass fibre reinforced PBT compounds. Food-contact polyesters must comply with Regulation (EU) No 10/2011 with migration limits for monomers. PEN used in bottles and packaging requires compliance with food contact material regulations. Biodegradable polyesters (PBS) may be certified under EN 13432.

Trade and customs procedures

When importing polyesters under CN code 390799, customs documentation should include precise polymer identification (chemical name, base monomer), MFI, melting point, any glass fibre reinforcement and commercial form. Duty rates should be verified in the TARIC system. PBT is produced by Celanese, BASF (Ultradur), DuPont, SABIC, Toray and Chang Chun. PTT is produced mainly by DuPont (Sorona) and Shell. The PBT market exceeds 1.5 million tonnes annually and is growing in automotive and electronics segments. Polyester granules are transported as non-hazardous goods. Preferential duty rates may be available under FTA agreements, provided proof of origin is documented.

Frequently asked questions

Which polyesters are classified under code 390799?
Code 390799 covers polyesters in primary forms not covered by codes 390710-390791, including polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), liquid crystal polyesters (LCP) and polybutylene succinate (PBS). It is a residual heading requiring precise polymer identification.
What is the difference between PBT and PET?
PBT (polybutylene terephthalate) and PET (polyethylene terephthalate) are both terephthalic acid polyesters but differ in the glycol used – PBT uses butanediol, PET uses ethylene glycol. PBT has faster crystallisation, better chemical resistance and lower moisture absorption than PET. PBT is classified under code 390799, PET under 390761 or 390769.
Does glass fibre reinforced PBT have a different CN code?
Glass fibre reinforced (GF) PBT in compound granule form is classified under the same code 390799. Under the Notes to Chapter 39, polymers in primary forms also include mixtures with fillers and reinforcements provided they retain the character of the base polymer. The technical specification should indicate glass fibre content.