BY Sola Ogundipe

The increasing risk of contamination by harmful mineral oils from the printing inks used on recycled cardboard packs is now a major concern especially for those who patronise fast food joints.

In tests on experimental packs of fine noodles, researchers found that food rapidly absorbed 10 times the recommended limit for concentration of these contaminating oils from the transport box.

• The monthly clean up execise for June was carried out by Macleans in conjunction with Ifelodun LCDA at Mosafejo, Ifelodun LCDA with a lot of fanfare last week. Wife of Chairman, Ifelodun LCDA, Alhaja Kudirat Adigun and others during the execise. Photo by Sylva Eleanya.

Experts say the world-recognised limit for these oils is 0.6mg in each kg of food, but researchers discovered that after standing in packaging for just six weeks, food could contain 6.1mg/kg. And this was in food that had a two-year shelf life, so it is quite possible the value could increase further over time.

Many foods such as rice, noodles, sandwiches, etc, are sold in paperboard boxes at the fast food outlets, where the recommended limit may be exceeded over 100 times. Even more foods are stored and transported in larger boxes largely consisting of recycled paperboard.

The research showed that even if the food was contained in clean paperboard boxes from fresh fibres, printed with inks free of mineral oil and wrapped into a polyethylene film (also free of mineral oil); mineral oils from the corrugated card transport box far exceeded the limit.

It was recognised that there is a tension between the need to recycle paper and board and the need to keep food free from high levels of these mineral oils. One of the presently discussed solutions could be to use paperboard made by recycling carefully selected, cleaner starting materials. But when the team ran tests using board with a mineral oil concentration approximately five times lower than usual , the mineral oil migration into the food still exceeded the limit about seven times.

Manufacturers could also use new wood fibres when making food packaging and transport boxes or introduce functional barriers against the migration of mineral oil, either as internal bags or lining the boxes with materials such as special plastics. This might be the way to go, but the technology is not ready and the recyclability of lined paperboard needs to be tested.