Plastic waste in Laboratories: Data, Reduction Strategies and Recycling Methods

The amount of plastic waste generated in laboratories poses a significant challenge to sustainability in the chemical industry. A widely cited estimate from 2014 puts the annual plastic waste from laboratories worldwide at around 5.5 million tonnes – equivalent to just under two per cent of global plastic production. This figure illustrates the scale of the problem and has triggered numerous waste reduction initiatives in recent years.

However, the actual amounts of waste vary greatly depending on the type of laboratory and its main activities. Recent surveys have determined an average plastic waste of 106 kilograms per laboratory employee per year. In laboratories that work with cell and tissue cultures, this figure is significantly higher at 237 kilograms per person. Analytical laboratories using standard methods, on the other hand, record lower amounts of around 166 kilograms per capita per year. These differences show that individual recording of waste generation – for example, over a representative period of one week or one month – is useful for identifying specific savings potential.

Reduction starts with Procurement

The largest share of greenhouse gas emissions is not generated during disposal, but during the manufacture of plastic products. An analysis of the carbon footprint of one hundred French laboratories revealed that the procurement of goods and services is responsible for around 50 per cent of total greenhouse gas emissions. In laboratories in the chemical industry, consumables alone account for 38 per cent of emissions – more than the purchase of equipment.

An effective strategy for reducing emissions therefore starts with consumption. Miniaturising approaches, using smaller volumes and adapting the size of containers to the actual sample quantity can reduce material consumption. For non-critical applications, the reuse of plastic materials is a good option. A documented example shows that a laboratory was able to save around 20,000 centrifuge tubes per year by systematically collecting, decontaminating, washing and autoclaving them.

The question of whether the resources consumed for cleaning and sterilisation exceed the cost of new production can meanwhile be answered on the basis of data. Comparative calculations for various plastic and glass items – including Erlenmeyer flasks, Pasteur pipettes, centrifuge tubes and Petri dishes – show that in all scenarios examined, the carbon footprint is lower for reuse than for new production. Reuse also proves to be more economical, even when personnel costs are taken into account.

Single-type Recycling as a Prerequisite for the Circular Economy

At the end of their product life cycle, single-use plastic materials are usually sent to thermal recycling. This is often because there is no documentation of the potentially hazardous substances with which the materials have come into contact. Under certain conditions, however, material recycling is also possible: the plastic waste must not be infectious or chemically contaminated and must be inactivated – i.e. autoclaved.

Various take-back programmes for laboratory plastics have been established, for example for PET media bottles or pipette tip racks. In some cases, a closed loop has already been achieved: the polypropylene recyclate obtained from the returned racks is used to manufacture new pipette tip racks.

For facilities with many different laboratories, single-type recycling requires systematic separation. Proven concepts rely on the selection of defined products – such as polypropylene tubes or polystyrene serological pipettes – which are collected in separate, clearly labelled containers. Material from safety laboratories is additionally autoclaved separately before being passed on to recycling companies.

Bio-based plastics are also gaining in importance. While first-generation plastics are derived from plants such as corn or sugar cane, second-generation materials use waste streams – such as used cooking oil from the food industry. Life cycle analyses for bio-based laboratory products such as tubes or pipette tips show savings of 18 to 27 per cent in CO₂ equivalents compared to fossil-based products.

Current Practice at Weserland

In production, transparent films are currently systematically collected and pressed into bales. These bales are sold as recyclable material. Other plastics that accumulate are collected and handed over to a waste disposal company. As these materials are neither sufficiently clean nor sorted by type, they are thermally recycled to generate energy.

Photo: Viktoriia Syvak

Source: Trade journal ‘Laborpraxis’