Naphthalene

Naftalen, Naftalen

 Naphtalene belongs to the group polycyclic aromatic hydrocarbons (PAH) and consists of two benzene rings bound together. It is a white, solid substance with an aromatic odour and has low water solubility.¹

Uses

Naphtalene has been used in pesticides against insects, mites, other arthropods, and as rat poison. Naphtalene is also used in production of solvents, fuel additives, motor oil and base oils, as well as in production of plasticizing chemicals for PVC (polyvinyl chloride) plastic.², ³, ⁴ Coal tar contains high levels of naphthalene and other PAHs.⁵

Sources and transportation pathways

Naphtalene and other PAHs are unintentionally formed during combustion. It is also present in fossil fuels and enters the environment during incomplete combustion in for example coke ovens and motor vehicles, as well as from cigarette smoke and small-scale wood burning. PAHs are also emitted to the environment during forest fires and volcanic activity. One important transportation pathway is by air, where naphthalene occurs in gas phase. Wastewater treatment plants are an important source of emissions to water.⁶ Industrial operations, such as production and processing of metals, paper and wood product processing and operations within the energy sector are important sources of PAHs.⁷

Use and spillage of products containing PAHs, for example fuel oil and fossil fuels, can lead to its presence in soil and water. Tyres containing high-aromatic oils (HA oils) contribute to the presence of PAHs in the environment through tyre wear as well as the recycling of tyres for manufacturing of rubber granulate that is used for artificial grass fields.⁸

Effects on environment and health

Naphtalene can cause long-term harm to the environment. It accumulates in the environment and is very toxic to aquatic organisms. It can cause long-term damage in organs and the nervous system, is harmful if ingested and is thought to be carcinogenic.⁹,¹⁰

International agreements and regulations

Polycyclic aromatic hydrocarbons are regulated by the UN Convention on Long-Range Transboundary Air Pollution (CLRTAP). Naphtalene is regulated by the EU Water Framework Directive (2000/60/EC). The presence of naphtalene in products is for example regulated by the EU regulation on Cosmetic products (EC 1223/2009). The UN Protocol on PRTRs and the EU E-PRTR regulation regulate how data on naphtalene emissions is made available.

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¹ https://rib.msb.se/
² https://rib.msb.se/
³ https://www.kemi.se/prio-start
⁴ https://toxnet.nlm.nih.gov/
⁵ http://www.asfaltskolan.se/res/PDF/stenkolstjraiasfalt_skllgesrapport0305.pdf
⁶ https://toxnet.nlm.nih.gov/
⁷ http://utslappisiffror.naturvardsverket.se/Sok/
⁸ https://www.kemi.se/prio-start/kemikalier-i-praktiken/kemikaliegrupper/polycykliska-aromatiska-kolvaten-pah
⁹ https://www.kemi.se/prio-start
¹⁰ https://rib.msb.se/