UNO Housing - additional information on plastic cages


* Housing recommendations according to the New EU Guidelines


* Choise of material for plastic cages

If you have to make the choise between polycarbonate or polysulfone cages purely for a costs point of view, you have to consider that the difference in costs between polycarbonate and polysulfone is 1:3. Therefore an investment in polysulfone can be justified if the lifetime of polysulfone is three times longer than the lifetime of polycarbonate. With a polycarbonate cage lifetime of about a 2 years, switching to polysulfone will start to be economically justified after six years. This can be considered a healthy investment. However if your lifetime of polycarbonate cages is 5 years, polysulfone will only become economical after 15 years. This is to be considered a riskfull investment due to new developments in the industry. We would like you to read the article of Mr. Leon Ernst that you can download here

 

* General guidelines about washing and sterilization

Polycarbonate

In the sterilization of animal cages made from polycarbonate the material may be damaged if there are alkaline cleaner residues or dried-on softened water on the surface. Consequently, any such residues must be completely removed by rinsing with fresh, alkali free water. The use of an acid rinse aid could prevent attack on the material. If soiled cages are autoclaved before cleaning, polycarbonate will be damaged.

Polycarbonate drinking bottles are generally cleaned using an acid cleaning process and finally rinsed well. Since the bottles are, as a rule, filled with water immediately after cleaning, the use of rinse aids is not required.

Polysulfone

Animal cages made from polysulfone are chemically more resistant than those made from polycarbonate and hence even allow autoclaving with soiled litter. Nevertheless, rinse cleaners should carefully be selected. Through the action of certain surfactants frequently used in cleaners and rinse aids, damage in the form of stress cracks can occur after autoclaving.

Washing

  • Use softened water.
  • Plastic cages should be washed at a temperature of max. 55˚C. Rinsing and neutralising during a short period of time can be done at about 80˚C.
  • Eventhough alkaline detergents are more effective in removing organic residues, when in contact with polycarbonate they will cause corrosions or hydrolysis. Therefore, if used, thorough neutralizing is necessarry.
  • Acid detergents can be used if urine or hard water scaling is a problem. Mostly there is no need to neutralize them.
  • Alkali detergents should not be used in case of hand washing, especially if sinking the cages in a pre-soak tank.

Autoclaving

  • Make sure no detergent and rinse aids residues are left on the surface; the autoclaving process will cause the residue to be baked on, which can cause chemical damage and loss in clarity of the material.
  • Use as short as autoclave cycle as possible. Minimum exposure of 20 minutes at 121˚C is recommended.
  • Do not stack more than 10 cages.
  • If you choose not to wash the cages before autoclaving, you must be aware that the left diet and bedding material could release damaging substances when heated. This could cause cracking of the plastic.
  • If you need to autoclave cages with bedding inside, use high quality bedding.

Disinfection

  • Do not heat cages or bottles that contain disinfectant residue.
  • Check with the supplier/manufacturer of the disinfectant regarding the use of the disinfectant on plastic cages.

* This information is a guideline only, based on generally available information.

 

* Heat-  and chemical resistance of polycarbonate and polysulfone material*

Autoclavable at

Max. Heat level Transparency Sterilisation
Autoclave Radiation Gas Dry-Heat Disinfect.
Polycarbonate PC 120 ˚C 138˚C

Clear

X
Polysulfone PSU 134 ˚C 165˚C Clear X
  • Max. heat levels: at this temperature a solid piece of plastic will deflect under a pressure of 66psi. Therefore it is not recommended to expose animal cages to these temperatures.
  • Autoclaving: during 20 minutes at 120˚C. It is highly recommended to clean and rinse the cages with softened water before autoclaving to prevent certain chemicals effecting the plastic during the autoclaving process.
  • Radiation: gamma irradiation at 25 kGy
  • Gas: Ethylene Oxide, Hydrogen Peroxide, Formaldehyde
  • Disinfect: Formalin, Ethanol, Formaldehyde, Benzalkonium Chloride

* This information is a guideline only, based on generally available information.

 

Chemical Resistance

Acids Dilute or weak

Bases Esters Oxidant Agents, strong
Polycarbonate PC Excellent Not recommended Not recommended Not recommended
polysulfone PSU Excellent Not recommended Not recommended Not recommended
  • Excellent: no damages after 30days of constant exposure.
  • Not recommended: Immidiate damage may occur; severe crazing, cracking, loss of strenght, discoloration and deformation.

* This information is a guideline only, based on generally available information.