If this product has an expiration or retest date, it will be shown on the Certificate of Analysis (COA, CofA). If there is no retest or expiration date listed on the product's COA, we do not have suitable stability data to determine a shelf life. For these products, the only date on the COA will be the release date; a retest, expiration, or use-by-date will not be displayed.
For all products, we recommend handling per defined conditions as printed in our product literature and website product descriptions. We recommend that products should be routinely inspected by customers to ensure they perform as expected.
For products without retest or expiration dates, our standard warranty of 1 year from the date of shipment is applicable.
For more information, please refer to the Product Dating Information document: https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/marketing/global/documents/418/501/product-dating-information-06-25-mk.pdf
1.07241
Phenol red
pH indicator, ACS
Synonym(s):
Phenol red
Select a Size
| Size/SKU | Availability | Price |
|---|---|---|
5 g | Estimated to ship onMarch 08, 2027 | $134.00 |
25 g | Estimated to ship TODAY | $336.00 |
100 g | Estimated to ship onAugust 10, 2026 | $1,180.00 |
1 kg | Estimated to ship onMarch 08, 2027 | $8,370.00 |
About This Item
Product Name
Phenol red, indicator ACS
grade
ACS reagent
Quality Segment
form
solid
loss
≤1% loss on drying, 110°C
visual transition interval
1.2-3.0, brown-orange to yellow(1st transition range), 6.5-8.0, brownish-yellow to red-violet(2nd transition range)
mp
>300 °C
bulk density
200‑300 kg/m3
storage temp.
2-30°C
SMILES string
[S]1(=O)(=O)OC(c4c1cccc4)(c3ccc(cc3)O)c2ccc(cc2)O
InChI
1S/C19H14O5S/c20-15-9-5-13(6-10-15)19(14-7-11-16(21)12-8-14)17-3-1-2-4-18(17)25(22,23)24-19/h1-12,20-21H
InChI key
BELBBZDIHDAJOR-UHFFFAOYSA-N
General description
Application
- Dye in the preparation of phenol red/n-Si photodiode [phenol red/n-type silicon wafer] by spin coating technique. The device is appropriate for photo-detection applications.
- Color-changing dye in the design of fiber optic pH sensor because as the acidity increases, the dye′s absorption properties shift from the green to the blue section of the spectrum.
- Indicator in the determination of freshwater pH.
Features and Benefits
- pH is 6.4 or below yellow color
- pH is 8.2 or above red color.
Analysis Note
1st transition range: pH 1.2 - pH 3.0brownish orange - yellow
2nd transition range: pH 6.5 - pH 8.0brownish yellow - red violet
Loss on drying (110 °C): ≤ 1
Transition range (according to ACS): passes test
ACS conforms
1 of 1
This Item | |||
|---|---|---|---|
| visual transition interval 1.2-3.0, brown-orange to yellow(1st transition range), 6.5-8.0, brownish-yellow to red-violet(2nd transition range) | visual transition interval - | visual transition interval 6.8-8.2, yellow to red | visual transition interval - |
| grade ACS reagent | grade ACS reagent | grade - | grade - |
| bulk density 200‑300 kg/m3 | bulk density - | bulk density - | bulk density - |
| storage temp. 2-30°C | storage temp. room temp | storage temp. room temp | storage temp. - |
| Quality Level 200 | Quality Level 200 | Quality Level 200 | Quality Level - |
| form solid | form powder | form powder | form liquid |
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signalword
Warning
hcodes
Hazard Classifications
Skin Irrit. 2 - STOT SE 3
target_organs
Respiratory system
Storage Class
11 - Combustible Solids
wgk
WGK 3
flash_point_f
Not applicable
flash_point_c
Not applicable
Certificates of Analysis (COA)
Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.
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How can I determine the shelf life / expiration / retest date of this product?
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How is shipping temperature determined? And how is it related to the product storage temperature?
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Products may be shipped at a different temperature than the recommended long-term storage temperature. If the product quality is sensitive to short-term exposure to conditions other than the recommended long-term storage, it will be shipped on wet or dry-ice. If the product quality is NOT affected by short-term exposure to conditions other than the recommended long-term storage, it will be shipped at ambient temperature. As shipping routes are configured for minimum transit times, shipping at ambient temperature helps control shipping costs for our customers. For more information, please refer to the Storage and Transport Conditions document: https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/marketing/global/documents/316/622/storage-transport-conditions-mk.pdf
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