Microbiological contamination is a major safety concern in all manufacturing cleanrooms. Microbial control is critical in preventing contamination, which could lead to fines, recalled products, and illness or death in consumers.

Sources of microbiological contamination include:

  • Contamination from cleanroom personnel, such as skin flakes, hair particles, fingerprints and clothing fibres.
  • Particles and bacteria exhaled by cleanroom personnel, such as viruses.
  • Contamination from dirty solvents or other liquids, such as bacteria in contaminated water.
  • Air particles carried in from outside, such as dust or aerosols.
  • Particles from cleanroom equipment, such as chips of paint from processing equipment or fibres from PPE material.

Microbiological considerations in cleanrooms

The type of microorganism found in cleanrooms is important, as different contaminants require different cleaning and decontamination methods.

A microorganism’s size, shape, optimal growth temperature, whether it produces spores, and its gram stain reaction should be considered. The results of these tests will help determine the source of the contaminants, as well as how to eradicate them. It is important to consider a number of factors:

Optimal growth temperature

Optimal growth temperature varies between microorganisms. Some thrive in warmer environments, up to 80 degrees Celsius, while others require colder temperatures to survive. The temperature of a cleanroom will affect that type of microorganisms that will grow and contaminate that environment.

Needed atmosphere

Like temperature, different microorganisms require different atmospheres to survive. Some, known as aerobic microorganisms, require oxygen to thrive, while others, called anaerobic, can continue to grow and multiply without oxygen. Other atmospheric considerations include whether it is a damp or dry environment and whether the microbe requires a lot to eat in order to survive.

Spore production

Not all types of microorganisms produce spores. However, those that do pose more of a threat to cleanroom environments, as they are harder to eradicate. Decontamination procedures that eradicate the microbes themselves may not kill the spores they produce.

Gram stain reaction

In cleanroom contamination prevention, gram staining involves categorising microbiological contaminants based on the structure of the cell’s outer wall.

‘Gram positive’ cells are the most common microbe found in cleanrooms, as they can be carried in on personnel’s clothing, hair or skin. These organisms don’t have an outer cell membrane and can produce spores, making them more difficult to eliminate.

‘Gram negative’ cells are found in damp environments, such as contaminated water, sinks, drains and pipes. They have a thin cell wall which is covered in an outer membrane. They are more dangerous than gram positive cells and can cause serious illness in humans.

Microbiological contamination level in the clean room environment is determined by various factors: including clean room personnel, microorganism growth temperature, room atmospheres, spore production and gram stain. However, by utilising the correct clean room garments and products, the risk of contamination can be managed by ensuring your cleanroom personnel are not a source of contamination.

Consider a managed rental service from Clean Room Garments, for your cleanroom garment needs. Our garments and clean room products are prepared in their very own cleanroom environment, which is qualified and certified to Grade B Cleanroom status. Complete your details in the contact us form and one of our helpful sales team will be in contact to discuss your clean room needs with you.