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Lean lab methods and safety in the laboratory

Workplace and process optimization using 5S as the basis for safety in the lab

Dipl. Ing. Erwin Studer (profact ag)

Holistic management systems such as Total Quality Management (TQM) and Lean Management aim to achieve the greatest possible added value for the customer while sustainably eliminating waste. The often underrated 5S method can provide the basis for creating a workplace organization that goes hand in hand with ergonomics and occupational safety.

The 5S concept has made its way into many laboratories, production facilities and offices around the world and, along with holistic optimization concepts, has increasingly moved back into focus. This method of workplace organization, which originated in Japan, aims to create lasting cleanliness and orderliness to maximize productivity and efficiency.

More than “Housekeeping”

Fig. 1 5S is derived from the acronyms of the Japanese terms; to adhere to the designation, equivalent English language S terms were coined.

5S derives from the Japanese terms seiri, seiton, seiso, seiketsu and shitsuke. They were originally translated as “organization”, “neatness”, “cleaning”, “standardization” and “discipline” in the English language book of the initiator of 5S, Takashi Osada, 1991 [1], and they were later modified to “organization”, “orderliness”, “cleanliness”, “standardization” and “discipline” (Fig. 1). To keep with using words that begin with the letter S, like the Japanese ones do, the equivalent English terms “sort”, “set in order”, “shine”, “standardize” and “sustain” were coined (Fig. 1).

The 5S concept established itself in Japan’s manufacturing industry, where the development of the Toyota Management System (TPS) under the chairman Kiichiro Toyoda laid the foundation for today's "lean production" principle. The engineer and head of production, Taaichi Ohno, further developed the TPS with methods such as the pull principle, just-in-time and kanban, which set the benchmark for today's successful global model of “lean management”. In the original Japanese context, the 5S principles were embedded into a holistic approach that went beyond workplace organization and was considered the basis and a necessary starting point within the lean management philosophy [2]. Applying 5S enables waste in processes to be made visible and subsequently reduced or eliminated. From the beginning, 5S also included a safety aspect, because orderly workplaces and reduced search times lead to fewer errors and accidents in the workplace. Hence, the additional sixth S for safety was already implied. A cross-sectional study by the Japan Industrial Safety and Health Association (JISHA, 1999) provided impressive evidence that the application of 5S led to a decrease in work-related accidents between 1945 and 1998, as reported by Gapp et al [2]. 5S is a comprehensive approach that goes far beyond cleanliness and orderliness, as the term “housekeeping” used as a synonym in the Western world suggests.

Safety in the laboratory is based on having and maintaining orderliness

Safety is often an issue during inspections at the beginning of a project or during auditing (Gemba walk), in the course of which unsightly work conditions or practices are noticed and can be taken into account. Safety issues are usually handled by the HSE (Health Safety Environment) units or departments.

Some renowned companies have therefore extended the 5S method by a sixth S (for “safety”), resulting in 6S or 5S+1. This sixth S can be quite useful in certain respects, but basic tasks such as workplace assessments, hazard potentials, biomaterials, REACH classes or instrument safety (e.g. autoclaves) are HSE responsibilities and should remain there. While the sixth S cannot replace the HSE specialists, it can be valuable and helpful to uncover any potential hazards and to avoid these.

Every employer is legally obliged to ensure the safety and protect the health of employees at work. However, the occupational health and safety organization must be adapted to the conditions and circumstances of each company individually. The task of safety supervision is performed by a specialist in occupational safety who is familiar with the industry.

Creating the conditions for working safely

A prerequisite for working safely is that cleanliness and orderliness at the workplace are consistently and systematically enforced, down to the smallest of details. These virtues apply all the more when, for example, active pharmaceutical substances (API) are handled in a laboratory.

This requires that

  • Employees are protected and not exposed to danger for unnecessarily long periods
  • Cross-contamination is prevented
  • The purity of substances is ensured

In addition to the technical and spatial requirements, e.g. for safety cabinets or isolators, the result depends on the underlying attitude towards orderliness and cleanliness. This helps to keep things in view, reduce unnecessary searches for work materials, make work processes more efficient and error-free and thus ensure impeccable, high-quality results.

From among the many “Lean” building blocks, the 5S method is an ideally suited tool to establish and/or constantly improve the conditions for safe working.

The safety aspects of 5S+1 at a glance

This overview introduces the individual steps of the 5S method, outlines their significance for safety in a laboratory environment and gives some practical tips in the course of implementing the method.

1. Sort (seiri)

© profact

Fig. 2 For the first step of 5S (sort), the traffic light color system approach has proved successful.

The first step is to decide if something is “needed”, “possibly needed” or “dispensable”, with “needed” items being subdivided according to the frequency of use (frequently, sometimes or rarely, as well as the quantity). This includes checking all materials, chemicals and equipment for their operational readiness. It should be done for all cabinets, drawers and racks, and at all premises.

The following procedure of sorting items according to the traffic light color system has proved effective (see Fig. 2):

  • Green: keep material/device and place back
  • Yellow: need is unclear; store for 3 to 6 months and discard if not used in that period
  • Red: discard material/device immediately

Safety aspect

Check cables for pinch points, check electrical grounding connections, ensure that safety glasses are available and in working order, check if tubing is in good condition, chemicals have not expired, etc.

Practical tip

Use the opportunity to clean all the cabinets that are emptied during the 1st S.

The 1st S needs good preparation, requiring things like disposal containers, cleaning equipment and labeling materials.

Do not underestimate the time needed for tidying up. Calculate about a half to one day per lab room.

2. Set in order (seiton)

© profact

Fig. 3 The third step of 5S is about creating visible orderliness.

In the second step, it is important to determine a fixed place for all materials (Fig. 3):

  • The remaining items are stored away systematically
  • Consider where and how to store
  • Attach labels or images

Safety aspect

Pay particular attention to ergonomics when placing things back into storage or reassembling equipment (if necessary). Are all switches and sockets mounted in a way that they do not pose any danger in the event of leaks or splashing liquids? Are multiple socket outlets mounted safely? What are the processes for handling hazardous substances?

© Mettler-Toledo, mit freundlicher Genehmigung

Fig. 4 Cleverly arranging the analytical equipment can minimize walking or transportation distances and times, allowing a workflow to be created.

Practical tip

The 2nd S also offers an opportunity to resolve the annoying issue of cables. Take the necessary time to do so. Your in-house electricians should have things like spiral cables, cable conduits or cable boxes available.

This step also gives the chance to consider where and how the equipment can be optimally placed. An unfavorable arrangement can make a lot of walking or transportation necessary. This can be visualized in a spaghetti diagram [see 3, Fig. 3 Workflow]. Where possible, the distances and transportation times should be minimized by cleverly arranging the analytical equipment so that a workflow can be created (Fig. 4). In addition to boosting safety, efficiency can be improved as well.

3. Shine (seiso)

Cleanliness has always been an important issue for laboratories, so a dedicated 5S method should not really be necessary. But in many laboratories, the old custom of rotational laboratory cleaning has unfortunately been lost. Responsibilities must therefore be assigned, cycles established, and the methods of cleaning determined.

Check lists (on paper or tablet) have also proved very useful, particularly if they include the required cleaning frequency (e.g. after every use, daily, weekly) as well as how and with what to clean.

Safety aspect

Many laboratories use the wrong or unapproved cleaning agents. Or when cleaning GMP zones, they use materials that generate particles and thus lead to abnormal monitoring results.

Practical tip

Perform "overhead" cleaning once a year. This should include the top of the cabinets, ventilation ducts, suspended ceilings, etc.

4. Standardize (seiketsu)

Rules and standards are important to ensure that order, cleanliness and improvements made are sustainable. Standards are also important for safety, which includes wearing protective clothing.

A standard helps to do something in the best, easiest and safest way. Key tasks:

  • Define and document locations/zones
  • Make the standard known and train staff
  • Include desks as well!

Practical tip

This also applies to the office of the laboratory manager/team leader! You cannot demand great efforts from your staff when you fail to be a role model yourself.

5. Sustain (shitsuke)

A lot of discipline is required to sustain orderliness and cleanliness. 5S audits should be scheduled at least twice a year. This can be done across departments as cross-auditing, or by your “Lean” organization. Nonconformities must be consistently followed up (Fig. 5). Key tasks:

  • Introduce audits for maintenance
  • Plan continuous improvement
  • Involve new staff as well

6th S: Safety

As mentioned at the beginning, some organizations go a step further and add a 6th S for safety in the laboratory to the classic 5S method.

© profact

Fig. 6 In the 6th S, it is important to develop an eye for unsafe work conditions and operations.

The idea of the 6th S is to take an in-depth look at conditions that normally cannot be scrutinized during a safety audit or walk-through, or that are not considered in enough detail. With regards to Figure 6 (waste containers for solvents), the questions could be: Are the collection containers in working order? Are the electrical grounding clamps pulled tight and free of corrosion? It is also important to develop an eye for unsafe work conditions and operations. If necessary, these can be prevented by applying Poka Yoke (Japanese for “avoid unfortunate mistakes”) methods.

Practical tip

Consider safety as an item on the agenda for Gemba walks and address it during the daily Huddle meeting under Safety on the Lean/SQCD board.

Finally, an unusual tip: Make your next “safety day” a little different by conducting it as “trainings of the other kind”: an interactive stage play. This is certain not to bore anyone and will increase attention quite substantially [4].


Applying lean methods such as 5S+1 in the laboratory is not a contradiction. In fact, they help to improve the conditions to ensure safe work. 5S+1 efforts can therefore create clean, safe and efficient workplaces. Personal protective material can be cleverly placed, which means less searching/retrieving and more time for the actual work tasks. The responsibilities for cleanliness in the workplace are clearly assigned, and successes become visible. Clear and concise processes also help for audits carried out by authorities or customers. To avoid staff skepticism, the support of specialists in “change management” can be helpful.


Category: Laboratory Management | Lean Laboratory

[1] Osada, T. (1991) The 5S’s: Five Keys to a Total Quality Environment, Tokyo, Asian Productivity Organisation
[2] Gap, R., Fisher, R., Kobayashi, K. (2008) Implementing 5S within a Japanese context: an integrated management system, Management Decision, 46(4), 565-579, DOI: 10.1108/00251740810865067
[3] Studer, E. (2015) „Work smarter not harder“ – Lean methods come to the lab…at last! q&more 2, 22-27, (German version: “Work smarter not harder – Lean-Methoden ziehen ins Labor ein… endlich!“), online version: https://q-more.chemie.de/q-more-artikel/208/work-smarter-not-harder.html
[4] Theater interaktiv, München: https://www.theater-interaktiv.net/

Date of publication: 23-Dec-2020

Facts, background information, dossiers

  • workplace organization
  • workflow management
  • active pharmaceutic…
  • audits

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    Dipl. Ing. Erwin Studer

    Erwin Studer, born in 1959, studied mechanical engineering at the University of Applied Sciences in Bern, Switzerland. Subsequently he spent much of his professional life in the pharmaceutical industry. Alongside work in factory planning, he became involved in laboratory planning and constr ... more

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