The availability of disposable cages for rats (EasyCage Rat 900) and mice (EasyCage Mouse) is of interest to Research Animal Houses dedicated to rodents that, depending on their size and in response to their operational constraints, have decided to generalise the utilisation of single-use cages or to use them from time to time or for specific applications. The utilisation of single-use cages is all the more worthwhile when they offer multiple utilisation possibilities: IVC mode or static and transport.
Furthermore, it may be critical to be able to apply this solution in a coherent way to the two main species of rodents used and, in some cases, to be able to use reusable or standard cages in parallel or successively without having to change to a different rack. With both types of cages, it is also particularly important to benefit from the performance of the racks’ ventilation system used for the reusable cages, whether in positive or negative mode.
For applications related to risk management at the level of animal houses, the “rat” and “mouse” disposable cages offer the same type of advantage and make it possible to apply this rodent accommodation solution in chemical or biological quarantine or confinement animal houses as described below.
Concerning rats, besides the obvious applications (always depending on the conclusions of the risk analysis and mitigation process) in biological confinement, utilisation also applies to chemical confinement, because this species is frequently used for ADME (Administration – Distribution – Metabolization – Excretion), bioavailability, pharmacokinetic, pharmacodynamics or drug safety (safety toxicology and pharmacology) type studies.
The interest is particularly marked with toxic test substances, for example:
- Carcinogenic, mutagenic or reprotoxic (CMR agents) chemical agents;
- Compounds radiolabelled with 14C, 3H and 125I isotopes for example;
- Very high pharmacological activity test substances according to the OEL (Occupational Exposure Limit) type categorisation.
Like with all primary confinement systems, the choice and method of utilisation are subject to the conclusions of the risk analysis / mitigation specifically associated with each project. In this context, the potential advantages of single-use cages are situated at the level of the decontamination, washing and waste management processes.
On that subject, what about the impact of disposable cages on the environment and waste management?
Of course, the ideal is to minimize the impact on the environment as much as possible, while benefiting from the operational advantages of single-use. However, there is no universal solution: on the one hand, regulations differ from country to country, and on the other hand, each site faces its own constraints and opportunities in terms of operational choices.
In some cases, the disposable cage has an operational and economic advantage: a substantial reduction in handling related to washing and cage preparation, and the elimination of electricity, water and detergent consumption. However, the ecological impact can be questioned with regard to the waste generated by single-use cages. The analysis and the resulting choice is site-dependent and multi-parametric: economic performance, supply and waste management, risk management, sustainable development.
In absolute terms, when it comes to waste treatment, incineration is the preferred method with the most ecological risk-benefit ratio. The use of an incinerator consists in recovering the waste treatment by recovering the heat released by the combustion of the waste, which is then recovered to:
- or supply a heating network;
- or to produce electricity.
Waste that is not sent to incineration is sent to landfilled, discharging toxic products and posing a risk to the environment. The intermediate option is recycling, but to date only 10% of plastic waste is recycled*.
It should be noted that waste treatment facilities vary from country to country. For example:
| Country | Population | Active combustion plants | Ratio |
| Germany | 81M | 601 | 1/135 000 |
| France | 66M | 127 | 1/520 000 |
| United Kingdom | 65M | 55 | 1/1 182 000 |
| It is therefore not always possible to incinerate. |
In the specific case of our industry, countries again have different regulations. Some countries do not consider disposable cages as biological waste and allow facilities disposed of them with “standard” waste. Other countries require facilities to use incineration, while others automatically classify them as biological waste. The table below summarizes the advantages and disadvantages / constraints to be taken into account according to the solution:
| Standard disposal of single-use cages | Sorting and management of single-use cages by a recycling process (incineration or recycling) | Single-use cage considered organic waste |
| This results in a very low cost and an impact on the environment. | This results in a low or even almost neutral impact on the environment. It is necessary to separate the cage and the litter. | This results in a low/neutral impact on the environment and the elimination of contamination risk. This solution complicates the operational process, with the need to decontaminate the cage after separation from the litter. |
Companies have taken an interest in cage recycling and offer a service for the handling waste of single-use cages. This relieves the facility of this responsibility and operational aspects, but clearly represents a financial cost.
Allentown strives to find solutions that are ecologically acceptable and economically viable in different situations.
*France, ADEME 2018 data.