How long does unmixed hair dye last

Q: Can you reuse hair dye after opening it?

You can only reuse dye that hasnt been mixed with a developer. If youve opened hair dye and havent mixed it with anything yet, youre 100% okay to close it again and reuse it later. What is this? Permanent and demi-permanent dyes are the only dye types that require mixing before application.

Q: How do you know if hair dye is expired?

If the color is fading really quickly, theres a good chance that the dye you used was expired. For instance, if your dye should last a month but fades after 2 weeks, the dye was probably past its prime. Sometimes, expired dye simply wont work, leaving your hair the same color it originally was.

Companies don't put expiration dates on hair dyes today since they basically last a lifetime if stored properly.

Índice Show

Why Does Hair Dye Expire or Go Bad?
Opened or Unopened Hair Dyes
Side Effects of Using Expired Hair Dye
How to Recognise if Your Hair Dye Has Expired
Why are There No Expiration Dates on Hair Dye Boxes?
Can I save leftover hair dye?
How long can you save leftover hair dye?
Can you reuse hair dye after opening it?
How do you know if hair dye is expired?

But they do go bad and if you still use them, you may suffer from a list of adverse side effects that might cause irreversible damage not only to your hair but to your skin, too.

So before you use that box of hair dye that's been lying around, here are the basic things you need to know about hair dye expiration.

Contents

1 Why Does Hair Dye Expire or Go Bad?
- 1.1 Opened or Unopened Hair Dyes
2 Side Effects of Using Expired Hair Dye
3 How to Recognise if Your Hair Dye Has Expired
4 Why are There No Expiration Dates on Hair Dye Boxes?
5 Conclusion

Why Does Hair Dye Expire or Go Bad?

Manufacturers attest that hair dye can last a lifetime, which is why they don't put expiration dates on the boxes or jars. But depending on how you store them, they can either last long or go bad.

Hair dyes go bad for a number of different reasons. Here are some of them:

You opened the packaging and air/sunlight has seeped in causing chemical reactions.
You stored it in a hot and humid place.
You mixed the dye and stored it in another container.
The dye is made of organic or natural ingredients - which expire faster than chemical grade dyes.

Opened or Unopened Hair Dyes

The average shelf life of an opened hair dye is 1-2 years while an unopened hair dye will last longer at 3 years.

When unopened, you have to store the hair dye in a cool, dry place, and away from direct sunlight and humidity. If you do so, the product will last up to 3 years in good condition.

But when opened, many factors will affect how fast your dye will expire. These are external elements in your environment that will cause the deterioration of the dye quality:

Direct sunlight - It will warm up or heat the chemicals, causing them to separate and rendering the dye useless.
Air - Air causes rapid oxidation. If the product contains peroxide, it will interact with the oxygen in the air and cause the dye to go bad.
Moisture - Moisture damages packaging if the hair dye comes in a box, and can lead to oxidation as well.
Micro-organisms - Bacteria and microorganisms can interact with the chemicals and thrive in the ammonia present in the dye, causing several chemical reactions that will cause the dye to go bad.

Side Effects of Using Expired Hair Dye

When hair dye is expired, its chemical makeup is permanently changed and thus, will react differently with your hair. Here are some of the side effects of using expired hair dye:

Dark Green Hair - This is one of the most commonly reported side effects from people who've used expired hair dye
Wrong Color - If indeed the dye still colors, the color on the box will not be the color that you get.
Uneven Color - If the dye still works, your hair will be in patches of different colors.
Frizzy and Brittle Hair - Caused by the change in the dye's chemical makeup
Burning Scalp and Hair Loss - Caused by the change in the dye's chemical makeup
Burning Sensation on the Skin, Redness Around Ears and Forehead

These side effects are some of the more common side effects as reported by users. You may react differently to the dye, but to be on the safe side, it is best that you avoid using expired hair dyes.

How to Recognise if Your Hair Dye Has Expired

If you're unsure whether the hair dye has expired or not, here are the things to watch out for:

Any Noticeable Swelling on the Packaging - Swelling on the packaging means air has seeped through the box or container and has caused oxidation. If the dye is contained in a hard container, no noticeable change in the packaging shape will occur.
Sings of Spoilage on the Cap or Lid - To check for spoilage when the dye is contained in a hard container, check the cap or lid. It is possible that the lid may have gotten loose and air had see[ed through. A yellowish or orange-y color around the lid will usually form.
Open the Hair Dye - Check to see if a water-like liquid has formed on top of the dye. If presence of this transparent liquid has occurred, then the chemicals have separated and your dye has gone bad.
Smell the Dye - If the dye lets out a bad, spoiled odor, then it had most likely gone bad.

If you don't find any of these signs but still want to make sure, you can call the manufacturer, give them the batch code of the dye you have, (which is found on the box) and the company will be able to give you the production date of the product. You can then gauge whether or not your unopened hair dye box has reached the maximum shelf life of 3 years or not.

Why are There No Expiration Dates on Hair Dye Boxes?

As mentioned earlier, most companies do not place expiration dates on their hair dye boxes since they can last indefinitely a long time when stored properly - especially for professional dyes, which contain a lot of chemicals that help preserve the dye.

Can I save leftover hair dye?

As for the leftover dye in a tube and a peroxide jar, those can be saved. It will be better if you manage to keep them in their native kit box they came in so that you could keep them all in one place together. So this is what you should do with different types of hair dye for saving it later.

How long can you save leftover hair dye?

Just put it into an air-tight container and store it in the fridge or at room temperature, and it'll last for about six weeks. While your color might not come out as saturated as it would have with fresh dye, it will still be safe to use.

Can you reuse hair dye after opening it?

You can only reuse dye that hasn't been mixed with a developer. If you've opened hair dye and haven't mixed it with anything yet, you're 100% okay to close it again and reuse it later. What is this? Permanent and demi-permanent dyes are the only dye types that require mixing before application.

How do you know if hair dye is expired?

If the color is fading really quickly, there's a good chance that the dye you used was expired. For instance, if your dye should last a month but fades after 2 weeks, the dye was probably past its prime. Sometimes, expired dye simply won't work, leaving your hair the same color it originally was.