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Knowledge Base: Questions About Hach Reagents


What is the shelf life of my reagents?

Hach formulates chemical reagents and designs packaging for as much stability and protection as possible. However, high temperatures, absorption of moisture or gases from the atmosphere, bacterial growth, or light can cause reagents to degrade and not function as intended. The chemical composition of the reagent, type of packaging and storage conditions all affect the shelf life.

Reagents should be stored in a cool (less than 25-30 °C), dry, dark place to ensure maximum shelf life. Some reagents, as indicated on the package label, should even be refrigerated. The shelf life may not be valid once a container such as a bottle has been opened. This is because contaminants from the atmosphere can enter the container and may react with the reagent remaining in the bottle.

When using solutions or bulk powders packaged in bottles, open the bottle for as short a time as possible, just enough time to pour or measure out a portion of the reagent, and then replace the cap tightly. This will minimize the risk of contamination. Also, once reagent has been removed from a container, never add it back to that same container.

The expiration date will indicate the end of the shelf life for that reagent. To find the expiration date for your reagent, click on "SUPPORT", then "Reagent Expration Date Lookup."

Reagents that have exceeded the expiration date may still function correctly; however, you need to verify this on a weekly basis using a standard solution in place of the sample (see the accuracy check section in your step-by-step procedure). Correct results using a standard solution with a concentration near the top of the range for the test will ensure that the reagent will function over the full range of the test. If you are running a test for a parameter for which there is no standard solution, such as ozone or sulfide, do not use reagents that have exceeded the expiration date.

Old reagents that do not function correctly should be disposed of according to the guidelines in the MSDS sheet and your laboratory quality assurance plan.

How do I translate Hach lot codes into date of manufacture?

Hach lot numbers contain a letter followed by four numbers, for instance A1096. The first number indicates the year the reagent was made. The next three numbers indicate the day of the year that the reagent was made.

For example, a lot number of A1096 indicates the reagent was made on the 96th day of 2001. The letter (A, in this example) has no relation to the date.

How should I dispose of reagents?

Each reagent has an associated Material Safety Data Sheet (MSDS), which gives advice on the safe use, storage, transportation, and disposal of that reagent. Review the "Disposal Considerations" section of the MSDS to find if your product is regulated by the USEPA as hazardous waste. If not regulated, the MSDS will desribe how to dispose of the product. If the product is regulated as hazardous waste, you will need to collect samples containing the reagent for disposal at a hazardous waste facility. You can find the MSDS for your reagent using the MSDS Download link under SUPPORT.

Federal disposal regulations may be superseded by state and local regulations, therefore it is important to consult with a regulatory agency in your area to be certain that you are in compliance for disposal of hazardous chemicals. The USEPA maintains a list of regulatory contacts that can answer all kinds of questions, from "Where is my local or state regulatory agency?" to "What is classified as a hazardous waste?" The list of contacts can be found at:

To properly dispose of the hazardous waste from COD Reagent Vials, view our ez COD™ Recycling Service Guide.

I received a reagent that says MDB or SCDB, what does this mean?

Both terms specify the packaging style of reagent bottles containing liquids. MDB stands for Marked Dropper Bottle to indicate that the bottle comes with an eyedropper that is marked to measure a volume of 0.5 or 1 mL. SCDB stands for Self-Contained Dropper Bottle. When inverted, this bottle will dispense drops one at a time.

I cannot find the MSDS for my reagent on your web site. Why not?

Please try entering the part number without the dash or hyphen. For example, rather than entering 14077-99, enter 1407799. If you still cannot find the MSDS, there may be a problem with the catalog number you are entering. You may not be entering the last two digits of the complete catalog number, or the last two digits may have changed.

The last two digits or suffix of Hach catalog numbers indicate the packaging size, for example 100 powder pillows or 500 mL. For example, the 99 in the catalog number 1407799 indicates that there are a quantity of 100 powder pillows contained in the package. At one time Hach MSDS sheets did not show the suffix; however, all Hach MSDS sheets currently show the complete catalog number including suffix. The best way to find the complete catalog number is to look on the product label. If the product is not available, try adding one of the more common suffixes listed below.

It is also possible that the packaging has changed slightly and the last two digits of the catalog number have changed. For instance, at one time PermaChem Powder Pillows that had a suffix of 49 were changed to a suffix of 99. Try changing the last two digits of the catalog number you have with a current suffix for that product to see if you are then able to download the MSDS. Differences in the last two digits of a catalog number do not indicate a change in product; therefore MSDS sheets for catalog numbers having different suffixes are identical.

The following suffixes are the most common for Hach reagents and standard solutions:

Permachem foil powder pillows:
     46, 66, 68, 69, 99
Plastic powder pillows:
     69, 66, 68
Bottled chemicals:
     01, 03, 11, 14, 16, 17, 23, 26, 32, 36, 37, 39, 42, 49, 53, 56
AccuVac Ampules:
Standard solution ampules:
     01, 12, 10, 16, 20, 50

If you still cannot find a MSDS for your item, it may be that one does not exist. Many products do not require MSDS sheets because they are either defined as articles (non-chemical) or as non-hazardous chemicals by the Federal Code of Regulations (29CFR 1910.1200). Products that are defined as articles include color cubes, color discs, and Gelex, SpecCheck, and DR/Check secondary gel standards. Products that are defined as non-hazardous include demineralized or deionized water, purified water, fluoride standard solutions, and zero standard solutions. It is also possible that the product (not just the suffix) is obsolete and no MSDS is available for it.

I've received a Hach reagent that is frozen. What should I do?

Hach tests reagents and standards to ensure proper function after freezing. If a Hach reagent solution or standard solution becomes frozen during shipment, allow the bottle to sit at room temperature until it is thawed, then mix by inverting repeatedly or shake. If crystals remain that will not go into solution, gently heat the bottle by placing it in warm tap water and mix well until the crystals are dissolved.

NOTE: At this time there are a few Hach reagents that may not go back into solution or function correctly if frozen - the Starch Indicator and PAO solutions. Please contact the Hach Customer Service Department if either of these products arrives frozen.

If there is any doubt about the quality of a reagent, it is always a good idea to test the performance by following the accuracy check section in the step-by-step procedure for the test you are running. If you can get the correct result using a standard solution, then you can be confident that the reagents and instrument are working properly and that you are performing the test correctly.

How do I use the demineralizer bottle to make demineralized (also called deionized or DI) water?

  1. Remove the cap from the demineralizer bottle and fill with tap water.
  2. Replace the cap. Shake the bottle.
  3. The demineralized water is ready for use. Flip the nozzle and dispense demineralized water as needed.

The demineralizer bottle may be refilled with tap water and used repeatedly until all the resin beads change from purple to yellow. When all of the beads are yellow, discard them and replace with fresh resin.

I just received this resin and half of the beads are already yellow. Shouldn't they be purple?

Half the resin beads are normally yellow, and half are purple. The purple beads contain an indicator that changes to yellow when the resin is saturated. The yellow beads work the same but do not change color when saturated. When all of the beads are yellow, discard them and replace with fresh resin.

Can I use two 5-mL powder pillows instead of one 10-mL pillow?

The 5-mL and 10-mL powder pillows differ only in the amount of powder in the pillows. In general, results will not differ if two 5-mL pillows are substituted for one 10-mL pillow.

However, it is advisable to confirm that you are getting correct results using a standard solution, or by comparison of a test using two 5-mL pillows vs. one 10-mL pillow.

The label on my broth or media for microbiological testing says that the expiration date is valid for storage at 2 - 8 oC, yet it was not shipped in a refrigerated truck. Will high temperatures during shipment change the shelf life?

Hach knows that during shipment, temperatures can be extreme. Therefore Hach has conducted tests of media at elevated temperatures to verify that the media is not adversely affected during shipping. As long as the media is refrigerated upon receipt, the expiration date given on the label is valid.