510(k) · Cleared
ClearedChlorine Sentinel II
Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly
Nelson Environmental Technologies, Inc. · MSY Strip, Test, Reagent, Residuals For Dialysate, Disinfectant
Cleared on Apr 11, 2025 as substantially equivalent to K193169 (Nelson Environmental Technologies, Inc., 2020) after a 113-day review. Its family tree reaches back 2 generations to 2009.
- Decided
- Apr 11, 2025
- Review
- 113 days
- Class
- Class II
- Product code
- MSY
- Recalls
- None
- Predicates
- 1
Its longest line of descent runs back 2 generations to K090338 (2009). No later device cites it as a predicate yet.
- Root · 2 generations backK090338 Ultra Low Total Chlorine, E-Z Chek Sensitive Total ChlorineReprocessing Products Corp · 2009
- 1 generation backK193169 Nelson Sentinel Series Basic Chlorine SentinelNelson Environmental Technologies, Inc. · 2020
- This deviceK243898 Chlorine Sentinel IINelson Environmental Technologies, Inc. · 2025
View FIG. 1 as a table
Line of descent and top descendants
| Generation | Number | Device | Applicant | Decided | Recalls |
|---|---|---|---|---|---|
| −2 | K090338 | Ultra Low Total Chlorine, E-Z Chek Sensitive Total Chlorine | Reprocessing Products Corp | 2009 | — |
| −1 | K193169 | Nelson Sentinel Series Basic Chlorine Sentinel | Nelson Environmental Technologies, Inc. | 2020 | — |
| 0 (this device) | K243898 | Chlorine Sentinel II | Nelson Environmental Technologies, Inc. | 2025 | — |
Sources: FDA 510(k) database (decision fields), the FDA summary (predicates and indications), FDA recall and enforcement reports, and MAUDE; processed by 510(k) Report. Verify on FDA.gov · Methodology and accuracy.
Planning a device in MSY? A 510(k) Report weighs predicate choices, recall history and review times for a new device like this one.
Top candidate predicates for a new MSY device
- #1 K222167 E-Z Chek Chlorine Residual Test Strips…score 4.2 · 1 generation · no Class I recall
- #2 Held for the reportin the report
What was it cleared against? (1)
Devices the submitter claimed this one is substantially equivalent to (*), and reference devices cited for a specific test or feature (†), as written in the FDA summary.
| Type | Number | Device | Decided |
|---|---|---|---|
| * | K193169 | Nelson Sentinel Series Basic Chlorine SentinelSummary page 5…Basic Chlorine Sentinel 510(k) Submitter / Holder Nelson Environmental Technologies, Inc. 510(k) Number K193169/S001 Regulation Number 21 CFR 876.5665 Water purification system for hemodialysis Class… | 2020 |
What descends from it?
No later submission names this one as a predicate yet.
Has anything in its family been recalled? (0 Class I)
No FDA recall names this device.
No ancestor or descendant has a Class I recall.
What does this lineage say?
- The line of descent spans 16 years and passes through 2 companies; a new generation was cleared every 11.5 years on median.
- None of the 2 ancestors has a recall.
How does its category compare?
All MSY devicesMSY Strip, Test, Reagent, Residuals For Dialysate, Disinfectant: FDA decisions, review times, recalls and adverse event reports over 20 years. 2025, this device’s year, is highlighted.
FDA decisions per year · MSY
1in 2025
2026 to Oct 25, outlined.
Median 510(k) review, days · MSY
Too few MSY 510(k)s in any year since 2007 to give a median.
Recalls per year · MSY
No recall names MSY since 2007.
Adverse event reports per year · MSY
1in 2011
MAUDE reports naming product code MSY, not matched to any one device; reports are not rates.
View these four charts as a table
| Year | Decisions | Median 510(k) review, days | Recalls (Class I) | MAUDE reports |
|---|---|---|---|---|
| 2007 | 0 | — | 0 | 2 |
| 2008 | 1 | — | 0 | 35 |
| 2009 | 1 | — | 0 | 0 |
| 2010 | 0 | — | 0 | 0 |
| 2011 | 0 | — | 0 | 1 |
| 2012 | 0 | — | 0 | 0 |
| 2013 | 0 | — | 0 | 0 |
| 2014 | 1 | — | 0 | 0 |
| 2015 | 0 | — | 0 | 0 |
| 2016 | 0 | — | 0 | 0 |
| 2017 | 0 | — | 0 | 0 |
| 2018 | 0 | — | 0 | 0 |
| 2019 | 0 | — | 0 | 0 |
| 2020 | 1 | — | 0 | 0 |
| 2021 | 0 | — | 0 | 0 |
| 2022 | 1 | — | 0 | 0 |
| 2023 | 0 | — | 0 | 0 |
| 2024 | 0 | — | 0 | 0 |
| 2025 | 1 | — | 0 | 0 |
| 2026 | 0 | — | 0 | — |
What is it indicated for?
The Chlorine Sentinel Il is intended for use by hemodialysis professionals as a secondary chlorine device to provide continuous monitoring of Combined Chlorine. It is not intended to replace the primary method of monitoring chlorine as part of the hemodialysis water treatment system. It functions completely independent of the water treatment system does not come into direct contact with feed water used to prepare dialysate.
Indications for use read by OCR from a scanned FDA summary, so letters may be misread. Check the PDF before quoting it.
https://510kreport.com/device/K243898 · printed Nov 6, 2026
Cite this page
510(k) Report. “K243898: Chlorine Sentinel II.” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 6, 2026. https://510kreport.com/device/K243898
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Record history
- FDA decision record loaded May 2, 2026
- Summary read Oct 13, 2026 (extraction version 9eaa42aa01ed)
- Lineage and recalls computed Nov 3, 2026
- Page last updated Nov 3, 2026