1. Introduction
The healthcare sector is known to be a large contributor to environmental pollution. On average, 5.5% of the total national carbon footprint of countries is from the healthcare sector, with developed countries such as The Netherlands, the United States (US), Belgium, and Japan in the lead with 7.6 to 8.1% [
1]. In 2013, the global disease burden due to the environmental impact of the U.S. healthcare sector was calculated to be 614,000 disability-adjusted life-years (DALY) annually [
2]. This paradox of healthcare having indirect adverse effects on public health calls for action to improve the environmental performance of the healthcare sector by energy savings as well as pollution and waste reduction [
3].
Being a very resource intensive part of the hospital, the operating room (OR) is an area where CO
2 emission saving measures potentially have a large impact. The carbon footprint of the OR is primarily determined by the use of inhalation anesthetics; energy use by the heating, ventilation, and air conditioning (HVAC); supply chain; and waste production [
4]. OR waste production is constantly growing, being partially explained by the increased use of disposable products in the last two decades. Disposables have replaced reusables and are nowadays the standard in healthcare. The rationale for this transition being infection prevention, cost reduction, and convenience. Many items that were once reusable in the OR have been replaced by disposable alternatives. Some examples are surgical gowns and drapes, laparoscopic instruments, and anesthetic equipment such as facemasks and breathing circuits. Discarding these disposables after use results in a considerable waste production that has become characteristic for the OR. In the meantime, a single operation generates an average of 12 kg of waste, causing the OR to be a major source of total hospital waste production [
4].
Although recycling is frequently considered as the primary solution to reduce OR waste [
5,
6], it is often difficult in an operating room setting because of a lack of knowledge of recyclable materials and the fact that it often involves the handling of infectious materials [
7]. Apart from these practical barriers to recycling, it is important to realize that the majority of packaging materials and disposable products used during operations are made of plastics and that recycling is actually downcycling of these products. In practice, recycled materials are rarely used as raw materials for similar products in the OR. Therefore, from an environmental perspective, it is better to reduce waste by first applying the other cornerstones for waste reduction “reduce”, “reuse”, and only then consider “recycle” [
8]. Recycling is an important way to ensure that valuable raw materials are not wasted in a circular economy. However, first and foremost, prevention of waste being generated is the best way to improve the OR’s environmental impact [
9,
10]. Surgery has in this a distinct opportunity to aid the transition to more environmentally friendly operating room strategies [
11].
The use of
blue wrap as disposable packaging material for sterile surgical instruments is a major contributor to OR waste [
7]. Estimates are that 115 million kilograms of
blue wrap is discarded on a yearly basis in the United States alone [
8].
Blue wrap is a multilayer non-woven packaging material made from polypropylene (PP) supplied as sheets. Surgical instrument nets are wrapped in the sheets, in a similar way as packages being wrapped (
Figure 1). Through the manufacturing process of spun bonding and melt blowing, a unique PP trilaminate is produced that is characterized by robustness and bacterial resistance and that withstands high temperatures necessary for the sterilization process [
12].
After unpacking sterile surgical instruments,
blue wrap packaging is discarded, making up 11.5% of total OR waste [
6]. Reducing OR waste is possible by considering reusable alternatives for perioperative disposables. An alternative to
blue wrap is a reusable rigid sterilization container (RSC) [
13]. However, no compelling evidence exists for whether the quality of either of these packaging systems would be better than the other. RSCs are used by the majority (60%) of sterilization departments in Europe, but much less in North America, China, and India, where
blue wrap is preferred [
14]. The overall total costs of purchase and use of both packaging systems are comparable [
15]. However, relatively large capital investments are required to purchase the containers, more storage space is needed, and the containers are ergonomically inferior because of their weight. These drawbacks of RSCs are a possible explanation for the worldwide popularity of
blue wrap.
For a number of perioperative textiles, surgical instruments, and anesthetic devices, a life cycle assessment (LCA) has been done and has shown reusables to be environmentally favorable to disposables [
16,
17,
18,
19,
20,
21,
22,
23]. However, this effect may depend on the local situation, as was evident in a LCA study of single-use anesthetic equipment where the results depended considerably on the power mix in the region of research [
24]. To this day, no LCA studies have been conducted to research the ecological burden of
blue wrap or RCA.
For the present study, our hypothesis was that, in the European situation, the use of the reusable RSC has less environmental impact than single-use blue wrap, even when closed loop upcycling is applied. This hypothesis was tested by two research questions investigating the following aspects: (A) the environmental advantage of RCS for high volumes (5000 use cycles) in big hospitals, and (B) the environmental break-even point of use-cycles for small hospitals.
An in-depth life cycle assessment was used to benchmark the two systems, cradle-to-grave, as well as for cradle-to-cradle (“closed loop”) solutions. The influence of the power mix will be examined as well in order to see the effect of local renewable electricity (i.e., electricity with a ‘bundled’ renewable energy certificate) or electricity of other regions of the world.
3. Results
3.1. The Environmental Gain for 5000 Cycles (Research Question A)
The results from the three indicator systems (carbon footprint, ReCiPe, and eco-costs) for 5000 use cycles of both packaging systems (
blue wrap and RSC) are shown in
Figure 5a–c.
In
Figure 5a, the carbon footprint scores of
blue wrap and the RSC are given for two scenarios: the current open loop situation and the future closed loop recycling. The current open loop situation gives by far the highest carbon footprint: 1869 kg CO
2e/5000 cycles. That carbon footprint can significantly be reduced by a closed loop system with mechanical recycling of the PP (shredding and melting): 883 kg CO
2e/5000 cycles. As mechanical recycling is downcycling (the quality of the PP deteriorates at each recycling loop), 10% virgin PP is added at the manufacturing plant. The RSC has the lowest carbon footprint of 285 kg CO
2e/5000 cycles for landfill and 270 kg CO
2e/5000 cycles for recycling. Closed loop scores hardly lower than the current open loop recycling in Western Europe. The reason for the small difference is that the RSC 5000 cycle case is dominated by the use-phase (i.e., washing and sterilization). See
Table A5 in
Appendix B.
The results in terms of ReCiPe points are given in
Figure 5b. ReCiPe is about damage in terms of human health, ecosystems, and resource depletion, and has no separate score for global warming. However, the toxicity of the carbon footprint (kgCO
2e) is rather dominant in human health. The reasoning is that global warming, i.e., higher temperatures, results in more diseases, and thus more DALYs.
For blue wrap (open loop), the CO2e component in human health in our calculations is 79%. That is the main reason that the ReCiPe results look similar to the results of the carbon footprint. It should be mentioned here that the uncertainty in these damage-based calculations on CO2 is rather high, because of the many calculation steps in the required calculations, and the many assumptions. This is in contrast to the prevention-based eco-costs of CO2.
For RSC (recycling), the CO2e component in human health is only 34%. The other main components are 31% for fine dust, 30% for the human health effect of water scarcity (caused by the rather high water consumption of the washing machine in the use phase), and 5% for human toxicity.
Another issue in ReCiPe is that resource depletion (e.g, the fossil fuels embedded in plastics) hardly counts in the system. Thus, the plastic waste mentioned in the Introduction is barely counted in ReCiPe.
It appeared in our research project that the eco-costs system provided the best basis for the analysis and communication. The calculation results are given in
Figure 5c. Characteristic for the eco-costs system is that materials’ scarcity has a relative high share of the total eco-costs of plastics (as well as metals), which makes eco-costs suitable for C2C calculations in the circular economy. Detailed data tables (per process step) for hot spot analyses are given in
Appendix B.
From
Figure 5a–c, it may be concluded that (a) the RSC system has much lower environmental pollution than the
blue wrap system and (b) the pollution of the
blue wrap system can be reduced to 50% or less when a closed loop recycling system is introduced.
It is obvious that these conclusions depend on the number of cycles as defined by the functional unit (the RSC becomes less attractive at less cycles). Thus, it makes sense to calculate the break-even point for both systems (blue wrap and RSC), which is relevant for small hospitals.
3.2. The Break-Even Points of Both Packaging Systems (Research Question B)
The potential environmental gain by the switch from a
blue wrap system to a RSC system, which has been calculated in the previous section, is interesting to big hospitals. Small hospitals might have a far lower functional unit than 5000 cycles. For these small hospitals, the break-even point of number of cycles is interesting (the question is, at how many cycles does the RSC have the same environmental burden as the
blue wrap system?). The answer to this question (our research question B) is depicted at
Figure 6a–c for carbon footprint, ReCiPe points, and eco-costs, respectively. The data were calculated for specific scenarios for end-of-life: the wraps are incinerated with heat recovery and the RSCs are landfilled.
For waste incineration with heat recovery (‘open loop’) and landfill of the RSCs (
Figure 6a–c), the break-even points are as follows: 98 cycles for the carbon footprint, 228 cycles for ReCiPe, and 67 cycles for eco-costs.
It is obvious that the break-even points are higher for the case of recycling of the wraps (closed loop mechanical recycling), as the eco-burden of the mechanical recycled wraps is much lower than the eco-burden of wraps from virgin PP. The results of the calculations are as follows: 150 cycles for the carbon footprint, 1293 cycles for ReCiPe, and 88 cycles for eco-costs.
Note that, in ReCiPe, the eco-burden of the closed loop blue wrap system (5000 cycles) is not much higher than the eco-burden of the RSC system; see
Figure 5b. Hence the high break-even point in ReCiPe.
3.3. Alternative Scenarios for Electricity of the Use-Phase (Sterilization and Washing)
The major component of the RSC system is the power consumption in the use-phase at the hospital: 1996 MJ per 5000 cycles; see
Table A5 and
Table A6 in
Appendix B. This triggers the discussion on the potential positive environmental effect of PV cells on the roof of the hospital. The positive effect in terms of eco-costs is given in
Figure 7. This figure also gives information for electricity in countries outside the EU.
Compared with the electricity mix in EU-27 (the base case), there is a potential reduction in the eco-cost of the RSC system of 28 euro per 5000 cycles (−74%) when electricity from local PV cells is used.
Note that the electricity in the use-phase for blue wrap is rather negligible: 103 MJ per 5000 cycles; see
Table A3 in
Appendix B.
4. Discussion
Disposable blue wrap is a very popular surgical instrument sterilization packaging system that is used by many sterilization departments in Europe, North America, China, and India. However, its use causes a great deal of healthcare waste and does not match the goal of a circular economy. In this context, it was hypothesized that choosing a reusable packaging system would be environmentally preferable.
This is the first peer-reviewed research into the environmental impact of RSCs and blue wrap. An LCA benchmarking study of these two packaging systems was executed. The main result of our study is that, in the European situation, an aluminum RSC, as a packaging system for surgical instrument sterilization, has 84% less eco-costs compared with the current three-layered, one-step, non-woven polypropylene blue wrap for a functional unit of 5000 cycles (which is the answer to our research question A). The advantage in eco-costs for the RSC already occurs after 68 out of 5000 use cycles (which is the answer to our research question B). The production phase of blue wrap is the main contributor to its eco-costs (88%), primarily owing to the PP pellets. For the RSC, the use phase (washing and sterilization) causes 93% of its eco-costs, primarily owing to the detergents and electricity usage.
In the context of regional differences in the energy mix of washing and sterilization, we modeled the effects on our results of switching to electricity generated exclusively by renewable energy sources or by bitumous coal power plants. This had hardly any influence on the results of blue wrap and only a moderate influence on those of the RSC (see
Figure 7 and
Table A6 in
Appendix B).
As an alternative to switching to the RSC system, we studied the impact of closed loop mechanical recycling instead of incineration of blue wrap as an end-of-life scenario. Modelling closed-loop polypropylene recycling reduced blue wrap eco-costs to 35%. However, in this scenario, the RSC still outperformed blue wrap ecologically by more than a factor of two.
The choice of a packaging system for sterile instruments may depend on many factors. Financial arguments may be important in this regard. For example, the RSC system requires upfront investment in washing and sterilization machines in addition to the purchase of the containers. The purchase of blue wrap is relatively inexpensive in this regard. However, Krohn et al. have shown that the total costs of ownership of these two systems are quite similar over time [
15]. They conclude that a choice for a particular system may then depend on the availability of financial resources for the necessary investments or that time savings in container handling may be a motive if there are personnel shortages. From a patient safety perspective, according to the guidelines, both systems are suitable as packaging for sterile instruments [
33]. However, a concern is the fragility of blue wrap, which, if damaged, may violate the sterile barrier [
34,
35]. This is the reason that containers are preferred in some cases such as when heavy orthopedic instruments are concerned.
Thus, switching from
blue wrap to RSC may have financial and practical consequences. If this is not desirable or the time is not yet ripe, a choice can be made to recycle
blue wrap. However, recycling medical plastics is challenging as separation in the workplace is difficult and there is the danger of potential infection hazards [
7]. In the case of
blue wrap, it is technically possible to reuse the recycled polypropylene as a raw material. Moreover, the risk of infection is low because
blue wrap can be collected cleanly before the surgery [
12]. However, contamination of the product in the sense of tape and the presence of chemical indicators must be taken into account.
Limitations due to modeling uncertainty and constraints are inherent to every LCA. The functional unit, impact indicator, and databases may each have an effect on the impact assessment. All data used from the Idemat (EcoInvent) databases are modeled and present limitations. The measures of impact found in different databases are generally comparable, though differences of 30% are possible. The eco-cost indicator is advantageous because it allows relatively easy and transparent calculations, there is no need for panel weighting of each impact category, and the results can be explained in terms of costs and measures to be taken.
We did not measure water and energy consumption, but calculated these from the manufacturer’s information. Moreover, estimates were made about the modes of transportation and, for certain production processes, alternatives were chosen because they were not available in the database registers. None of these are expected to have a significant influence on the final results. With regard to the water and energy consumption, even a doubling of the eco-costs of the use phase of the RSC would not alter the conclusions drawn. The transport phase of both RSC and blue wrap is a relatively small part of the eco-costs (0.2 and 5%, respectively), which makes it unlikely that alternate assumptions would suddenly dominate the results.
Only three-layered, one-step, non-woven polypropylene wrap and RSCs made of aluminum were included in our study, as these are the two most widely used systems in the world. However, there are other packaging materials available for surgical instrument sterilization that may show different results; for example, other multilayer non-wovens, paper, cotton, and mold bush drums. The latter two are mainly still used in developing countries, as they do not meet the ISO standard (11607) for sterilization packaging materials.
Future research should be directed at executing more LCAs of disposable items found in the OR, as they are known to be a significant contributor to its carbon footprint [
4]. Much research that has been done on the carbon footprint of the OR has focused on the effects of inhalation anesthetics, HVAC, and waste production. A small number of LCA studies have already been done [
16,
17,
18,
19,
20,
21,
22,
23], but for many disposable items in the OR, the answer to the question regarding the environmental impact has not yet been given.
5. Conclusions
This study shows that the use of a rigid sterilization container has 84% less eco-costs than when blue wrap is used to package surgical instruments for sterilization. This difference is of such an order of magnitude that the container is more environmentally friendly after only 68 of the 5000 use-cycles.
When the choice of blue wrap as a packing system is made, recycling blue wrap is an option. In the closed loop recycling scenario, with all three single indicators, there was a halving of the pollution from the blue wrap system compared with the cradle-to-grace system.
The widespread use of disposable
blue wrap packaging in developed countries is an example of health care pollution that could be reduced by opting for reusable sterilization containers. With a healthcare system that is co-responsible for the impact of pollution on public health, it is the role of doctors and healthcare managers to point out the need for a transition to circular management in their industry [
36]. Our results show ecological benefits that must be included in the decision making process of procurement.
Doctors should be conscious of how encultured disposables like
blue wrap have become in healthcare. Often, unrealistic expectations regarding infection prevention, perceived price benefit, and ease of use underlie the choice for disposables [
37]. We need to be more informed of the destructive effects of our disposables on the environment and demonstrate which alternatives exist on the basis of LCA-driven scientific research. Our reliance on healthcare disposables has resulted in excessive wastage and pollution and has exposed us to supply chain vulnerability, as the current COVID-19 crisis has made painfully clear.