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Short answer
5S is a workplace-organization method built on five steps: Sort, Set in Order, Shine, Standardize and Sustain. The US EPA describes it as a system to reduce waste and optimize productivity through an orderly workplace and visual cues. In a laboratory it translates into clearing out obsolete equipment and outdated reagents, labeling storage so items are easy to find, keeping surfaces clean enough to show leaks, and writing the routine down so it lasts.
Definition and scope
The five terms come from Japanese: Seiri (Sort), Seiton (Set in Order), Seiso (Shine), Seiketsu (Standardize) and Shitsuke (Sustain). The EPA presents 5S as part of its lean thinking and methods material, where it is a tool for removing waste from how a space is arranged and used. It is a housekeeping and organization method. It is not a laboratory safety standard, an accreditation requirement or a substitute for either,.
How 5S is used in practice
The EPA describes the steps in a fixed order, and the order matters because each step prepares the next.
Sort (Seiri)
Remove unnecessary items from the workplace. The EPA describes red-tagging items and moving them to a holding area, from which they are disposed of, recycled or reassigned. Sort is therefore a decision about each item, not a tidy-up.
Set in Order (Seiton)
Arrange and label storage so that items are easy to find and easy to return. This comes after Sort, so that storage is designed only for what is staying.
Shine (Seiso)
Clean the work area regularly. The EPA notes that working in a clean environment enables workers to notice malfunctions such as leaks and misalignments, which is why cleaning is treated as inspection and not only appearance.
Standardize (Seiketsu)
Create a consistent approach to how tasks and procedures are done. The EPA’s description includes assigning 5S duties, building them into routine work and checking compliance. In a lab this is where the routine meets a written standard operating procedure (SOP).
Sustain (Shitsuke)
Make the practice a habit. The EPA calls this often the most difficult S to implement and achieve, because teams tend to revert to earlier habits.
The five S’s in a laboratory setting
The first column below is the EPA description of each step. The third column shows how the step appears in the Rush University prep-room case described below, and notes where that case reports nothing.
| Step | EPA description | Laboratory example (Rush prep room) |
|---|---|---|
| Sort (Seiri) | Remove unnecessary items; red-tag and hold for disposal, recycling or reassignment | Obsolete equipment and outdated reagents removed |
| Set in Order (Seiton) | Arrange and label storage so items are easy to find and return | Not reported in the case |
| Shine (Seiso) | Clean regularly so malfunctions such as leaks and misalignments are noticed | Not reported in the case |
| Standardize (Seiketsu) | A consistent approach to tasks and procedures, with duties assigned and compliance checked | Not reported in the case |
| Sustain (Shitsuke) | Make it habit; the EPA calls it often the most difficult S | Not reported in the case |
A worked laboratory example
A 2018 article in Clinical Laboratory Science (volume 31, issue 3, page 161) by L. Gillard, “Using Lean 5S to Optimize MLS Laboratory Work Space”, reports a 5S project in the Medical Laboratory Science prep room at Rush University in Chicago. The Sort step removed items that were no longer valuable, including obsolete equipment and outdated reagents. Before the project the prep room held two extra refrigerators and an extra freezer. The only figure the article reports is 35% more work space. One prep room at one university is a single data point; it shows what Sort can free up, not what any other lab should expect.
Where it matters for labs and supply decisions
- Surplus equipment. The Rush case found extra refrigerators and a freezer in a prep room. Cold storage that holds little is still equipment to power, clean and maintain; see the CASRAI guide on ultra-low temperature freezer maintenance for what that upkeep involves.
- Outdated reagents. Sort treats reagents past their usefulness as items to remove. Chemicals leave the room through waste rules, which start with hazardous waste determination.
- Storage space. The EPA notes that less storage space decreases the energy needed to heat and light the space.
- Tracking what is on hand. Set in Order assumes you know what is in the room. CASRAI’s comparison of laboratory inventory management software covers tools labs use for that record.
Environmental trade-offs the EPA flags
Most 5S summaries list only benefits. The EPA’s page adds two cautions. Regularly painting and cleaning machines and equipment could lead to increased use of paints and cleaning supplies. And disposing of unneeded equipment and supplies creates a short-term surge in waste generation. Both fall on the consumables and disposal side of a lab’s operations, so a Sort day should be planned with its waste stream in mind.
Common misunderstandings
- “Sort means tidying up.” In the EPA’s description it is a decision about each item, with red-tagging and a holding area so that disposal, recycling or reassignment is chosen deliberately.
- “Once the room is organized, the work is done.” The EPA identifies Sustain as often the most difficult S, because teams revert. Standardize, with assigned duties and compliance checks, is the step meant to prevent that.
- “5S is about looks.” The EPA ties Shine to noticing leaks and misalignments, and Set in Order to finding and returning items easily.
- “5S replaces safety or regulatory requirements.” 5S is an organization and waste-reduction method. It does not replace any safety or compliance obligation, which stay with the lab’s own procedures and the rules that apply to it.
FAQ
What does 5S stand for?
Sort, Set in Order, Shine, Standardize and Sustain, from the Japanese Seiri, Seiton, Seiso, Seiketsu and Shitsuke.
What is the hardest S?
The EPA says Sustain is often the most difficult S to implement and achieve, because teams revert to old habits.
Is there a sixth S?
The EPA describes five steps, and those five are the core method. Some organizations extend it with additional steps, but that is a local variation rather than part of the EPA description.
What happens to items removed during Sort?
In the EPA’s description they are red-tagged and moved to a holding area, then disposed of, recycled or reassigned.
Sources
- US Environmental Protection Agency, Lean Thinking and Methods: 5S, checked 2026-10-29.
- Gillard L. Using Lean 5S to Optimize MLS Laboratory Work Space, Clinical Laboratory Science 2018;31(3):161, ASCLS, checked 2026-10-29.
