The Maritime and Port Authority of Singapore (MPA) said Thursday that exhaust gas cleaning residues generated by ships are classified as toxic industrial waste, meaning they need to be collected and managed by licensed toxic industrial waste collectors (TIWCs).

“Ships that wish to dispose of exhaust gas cleaning residues in Singapore are required to engage a licensed TIWC for the collection and disposal of such residues,” the MPA said in a statement.

“TIWCs can arrange for the residues to be offloaded in packaged form or in intermediate bulk container tanks directly to trucks and MPA licensed harbor craft for ships at berth and at anchorages, respectively.” The classification of residues created by exhaust gas cleaning systems, or scrubbers, as toxic waste follows Singapore’s ban of the use of open-loop scrubbers in its port waters from January 1, 2020.

The ban of the use of open-loop scrubbers in certain ports, paired with the potential costs arising from the need to engage TIWCs to collect the residues, may further discourage the purchase of open-loop scrubbers.

Under the current proposals, there is largely expected to be a two-tier market in the shipping markets.

Those with scrubbers installed will benefit from a lower costs of fuel than their non-scrubber fitted competitors, but will burden additional costs associated with the disposal of exhaust gas cleaning residues.

Also worth noting is that scrubbers are not cheap. A unit costs anything between $2 million and $6 million per vessel, which with additional costs associated with the disposal of the residue attached, may paint a less rosy picture for those contemplating installing open loop scrubbers.

This also comes alongside the fact that they have already been banned in key bunkering hubs like Singapore and Fujairah as well as Belgium, California, Massachusetts and along the River Rhine in Germany, potentially adding further complications and requiring alteration of routes and bunkering hubs to reap the benefits of the aforementioned cheaper fuel.