Materials Recovery Facilities (MRFs)
Materials Recovery Facilities (MRFs), also known as Materials Recycling Facilities or Materials Reclamation facilities, may be designed to handle materials collected from a single municipal/household kerbside collection system, or more typically, to sort materials from a number of kerbside collection programmes, as well as recyclables from commercial and industrial sources. These operations range in size and are operated by local authorities, major private contractors, the community/third sector and SMEs who may also operate waste transfer stations.
They can play an important role in reducing the amount of waste sent to landfill sites. They are specialised plant that receives, separates and prepares dry recyclable materials. The recyclables go through a variety of mainly mechanical and some manual processes to obtain maximum recovery of materials that will re-enter the manufacturing process as a valuable commodity. The recyclable waste is typically separated into:
- Glass (not in all feedstock)
- Aluminium and steel cans
- Plastic bottles and packaging
- Other, non-recyclable residual material
MRF facilities may use a range of technologies to sort recyclables by their physical and chemical properties; shape, size, weight, magnetism and optical scanning (paper and plastics. Although the recycling and sorting of waste is increasingly more sophisticated and mechanised, there remains a significant reliance on manual operations, particularly hand-picking, to ensure quality standards are met.
- Designing and operating material recycling facilities (MRFs) safely (WASTE13)
An example of a schematic layout for a typical MRF (in practice there will be many different variations) that deals with dry recyclable waste is shown:
Process flow description
Waste to be processed is unloaded in the tipping area (1) and grab loaded (2) into the receiving hopper for conveying (3) into the trommel (4).
The rotating trommel sorts the material into three different sizes. The fist stream leaving the trommel on the fines conveyor (5) transport cans through an over band magnet (6) and an eddy current separator (8) to separate steel and aluminium constituents, respectively. The residue from these sections is fed by conveyor (15) to a stockpile (16) for onward disposal.
The two other streams from the trommel (9 &10) carry paper, cardboard and plastics to the main picking station (11). Here a number of operatives (pickers) hand sort the individual components dropping the individual recyclates into individual storage bays (12) beneath the picking floor. From the storage bays the sorted materials travel on a conveyor (13) to a baling machine (14) for packaging prior to disposal.
Other conveyor locations in the process (eg, 7) may also have operatives engaged in hand picking to ensure quality requirements are met.
The throughput of the plant is controlled by a supervisor in the control room (17).
The assistance of Grundon Waste Management Ltd is acknowledged in the preparation of this schematic information.
Useful additional information on the range and types of MRFs is available from the Waste & Resources Action Programme (WRAP) website.
Ergonomics at materials recovery facilities
Conveyor belts are used in a range of industries to move materials. Using these systems in the workplace can reduce the risks of musculoskeletal injury (MSD) by avoiding the need for excessive repetitive bending, lifting and carrying.
In MRFs conveyor belt workstations (picking-stations) should be properly designed to ensure that operators do not excessively lean, stoop, twist, or over-reach, since these repetitive movements can themselves lead to musculoskeletal injury.
The workplace lay-out, size of the conveyor, type, through put and height of material, and how material is handled, are all factors to consider when assessing the risk of MSDs in a task undertaken at a conveyor.
The guidance below considers these and many more issues, and gives practical, well-illustrated solutions.
Noise in Material Recovery Facilities
Most MRFs have processes which emit high noise levels exceeding the 80dB(A) and 85dB(A) levels at which employers are required to take action under the Control of Noise at Work Regulations 2005.
The following guidance identifies the areas where the equipment in a MRF is likely to expose employees to excessive noise levels, the likely exposure and suggested methods of controlling the risk.
Occupational hygiene implications of processing waste at Materials Recovery Facilities
The processes involved during recycling at MRFs can generate organic dust, which may lead to exposure to airborne microorganisms and their toxic by-products. This may cause health problems in workers who are involved in the handling waste.
There is a the potential for employees working in MRFs to be exposed to general airborne dust above the level where it is considered a substance hazardous to health (10 mg/m3 as an 8-hr TWA). In addition, there is also the potential for exposure to agents which are known to have harmful effects on human health such as fungi, bacteria and endotoxins.
What do you need to do?
As a dutyholder you should take the health issues associated with exposure to dust and airborne microorganisms into consideration, assess the risk and determine the control measures required. You should ensure that there is:
- provision of suitable and sufficient COSHH risk assessments;
- provision of adequate welfare and hygiene facilities;
- provision of a risk-based health surveillance programme;
- control of inhalation exposure to hazardous substances by the effective use of general ventilation, Local Exhaust Ventilation (LEV) the appropriate use of respiratory protective equipment (RPE); and
- provision of training and supervision;
Further information is available in research report RR977 - Occupational Hygiene implications of processing waste at Materials Recycling Facilities (MRFs): Exposure to bioaerosol and dust.