Sains Malaysiana 44(9)(2015): 1263–1268

Biodegradation of Palm-based 9,10-Dihydroxystearic Acid (DHSA) in Aquatic Environments

(Biodegradasi Asid 9,10-Dihidroksistearik berasaskan Sawit dalam Persekitaran Akuatik)

RAZMAH, G*., SITI AFIDA, I., NOORAZAH, Z. & HAZIMAH, A.H.

Malaysian Palm Oil Board, 6, Persiaran Institusi, Bandar Baru Bangi, 43000 Kajang, Selangor Darul Ehsan, Malaysia

Diserahkan: 19 Mac 2015/Diterima: 29 Mei 2015

ABSTRACT

Palm-based DHSA is a new chemical developed in MPOB that has three reactive sites that would enable the preparation of many useful derivatives. New chemicals introduced into the market have to be registered and information on their environmental performance such as biodegradability has to be supplied as required under various national and international laws. Biodegradability screening tests, such as the OECD 301 series, are basic tools for assessment of the environmental fate of chemicals in aquatic environments. A substance is considered readily biodegradable when its biodegradability reaches the pass levels of 60% carbon dioxide (CO₂)/theoretical carbon dioxide (ThCO₂) evolution, 60% biochemical oxygen demand (BOD)/theoretical oxygen demand (ThOD) or 70% dissolved organic carbon (DOC) removal within 28 days. Palm-based DHSA was found to be readily biodegradable where its biodegradability reached 65% within 28 days test period determined via the OECD 301C Modified MITI (I) test method, which passed the 60% level of BOD/ThOD requirement as stipulated in the OECD Guidelines for testing of chemicals. This result is indicative of DHSA’s rapid degradation in aquatic environments. Hence, DHSA is not expected to accumulate in the food chains and will not pose problems in the aquatic environments although it is poorly soluble in water.

Keywords: Aquatic environments; MITI test; OECD ready biodegradability test; OECD 301C test; REACh

ABSTRAK

DHSA adalah bahan kimia baru berasaskan sawit yang dibangunkan di MPOB. Ia mempunyai tiga tapak reaktif yang membolehkan penyediaan banyak bahan terbitan berguna. Bahan kimia baru yang diperkenalkan ke dalam pasaran perlu didaftarkan dan maklumat mengenai prestasi alam sekitar mereka seperti biodegradasi perlu dibekalkan seperti yang dikehendaki di bawah pelbagai undang-undang tempatan dan antarabangsa. Ujian saringan biodegradasi, seperti siri ujian OECD 301, adalah ujian asas yang boleh digunakan untuk menilai kesan bahan kimia dalam persekitaran akuatik. Suatu bahan boleh dianggap sebagai mudah terbiodegradasi apabila peratus biodegradasinya mencapai tahap lulus 60% karbon dioksida (CO₂)/evolusi karbon dioksida teoretikal (ThCO₂), 60% permintaan oksigen biokimia (BOD)/permintaan oksigen teoretikal (ThOD) atau 70% penyingkiran karbon organik larut (DOC) dalam tempoh 28 hari. DHSA berasaskan sawit didapati mudah terbiodegradasi, dengan kadar biodegradasi mencapai 65% dalam tempoh 28 hari yang ditentukan melalui ujian OECD 301C diubahsuai MITI (I). Nilai ini telah melepasi tahap 60% BOD/ThOD yang diperlukan seperti yang dinyatakan di dalam garis panduan OECD bagi menguji bahan kimia. Keputusan ini adalah penunjuk kepada kemerosotan pesat DHSA dalam persekitaran akuatik. Oleh itu, DHSA dijangka tidak akan berkumpul dalam rantaian makanan dan tidak akan menimbulkan masalah dalam persekitaran akuatik meskipun ia kurang larut dalam air.

Kata kunci: Persekitaran akuatik; REACh; ujian MITI; ujian OECD sedia terbiodegradasi; ujian OECD 301C  

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*Pengarang untuk surat-menyurat; email: razmah@mpob.gov.my