Fuel testing agency Maritec-Naias has issued a warning over elevated levels of phenolic compounds detected in bunker fuels lifted at several Chinese ports, according to a Bunker Flash alert reported by Ship & Bunker.
According to Ship & Bunker, Maritec-Naias examined fuel samples from vessels that bunkered in China between June 7 and July 28, identifying ten cases where phenolic compounds and their derivatives were present at concentrations ranging from 5,200 to 15,750 ppm. The affected supplies were traced to five ports: four samples from Tianjin, two from Qinhuangdao, two from Rizhao, one from Zhoushan, and one from Shandong, Ship & Bunker reported.
Stability and Operational Concerns
The report states that samples containing phenolic content above 5,000 ppm achieved only a “marginally stable” classification, with P-values ranging from 1.00 to below 1.30 under the firm’s stability reserve test. Maritec-Naias cautioned that prolonged storage of fuels at these levels raises the risk of reduced stability over time.
According to Ship & Bunker’s coverage of the alert, similar phenolic concentrations have previously been linked to excessive sludge formation in purifiers, filter choking, and increased wear on fuel pumps. The compounds were identified using gas chromatography-mass spectrometry, and Maritec-Naias suggested they may have originated from liquid fuels derived from coal tar or shale-derived oil.
Compliance Implications
Maritec-Naias argues that the contamination renders the fuels unacceptable under the general requirements of ISO 8217 and MARPOL Annex VI Regulation 18, regardless of whether the fuels comply with the standard’s Table 2 parameters, Ship & Bunker reported.
The testing firm advised affected vessels to closely monitor fuel systems for filter clogging and purifier sludging, to increase de-sludging frequency, and to avoid blending the fuel with other products—particularly marine diesel and gas oil—since mixing may worsen sediment formation. Maritec-Naias also noted, as cited by Ship & Bunker, that while its findings are accurate, they do not necessarily reflect the overall quality of fuel supplied across China.
Does This Matter to You?
Vessel operators bunkering at Tianjin, Qinhuangdao, Rizhao, Zhoushan, or Shandong may want to review recent fuel deliveries in light of these findings, particularly given the operational risks flagged around purifier sludging, filter choking, and pump wear. Bunker traders and fuel buyers sourcing from these specific Chinese ports during the June-July window covered by the samples may also find this relevant when assessing fuel quality documentation.
Because Maritec-Naias contends the affected fuels could be considered off-spec under ISO 8217’s general requirements even when Table 2 parameters are met, this raises questions for compliance monitoring beyond standard specification checks. The source material does not indicate the scale of the affected fuel volumes or whether specific suppliers have responded, so the broader market impact remains unclear.
Gulf Bunkering does not provide operational or security guidance. This article is for informational purposes only. Operators should consult flag state authorities, P&I clubs, and relevant advisories for decisions relating to transit planning.
Sources: Ship & Bunker
