Ingredient review

HC Orange No. 2

INCI: HC Orange No. 2

HC Orange No. 2 is a synthetic dye that adds orange shades to hair color, but it may cause irritation in sensitive individuals and has limited long-term safety data.

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In plain English

HC Orange No. 2 is a man-made color molecule that sticks to the outer layer of your hair (the cuticle) to give it an orange tint. It's commonly found in semi-permanent hair dyes that wash out over several shampoos. Because it's a dye, it doesn't lighten hair—it only deposits color on top. Think of it like a temporary stain for your hair, similar to how a marker colors paper. It's not meant for skin or nails, only for coloring hair.

Review score

Safety, usefulness, and evidence

3.5Good

3.5/ 5

Potentially useful with some tradeoffs

The evidence base is useful, but some claims depend heavily on the formula.

Main practical flags: irritation is moderate; clogging risk is low.

Source: synthetic
Evidence: moderate
Irritation: moderate
Clogging risk: low

How reviews are scored

Quick decision guide

Useful, but context matters

HC Orange No. 2 can be useful, but watch for some irritation potential.

Plain-English read

Treat this as a practical screening step before you compare products that contain this ingredient.

Step 1Start with the score, then check the irritation and clogging risk before judging HC Orange No. 2.
Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.

Score terms in plain English

Irritation risk

moderate

Can bother some users, especially with frequent use, damaged skin, or strong companion ingredients.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

HC Orange No. 2 is a synthetic azo dye, meaning it contains a nitrogen-based chemical structure that gives it its orange color. It belongs to the HC (Hair Color) family of dyes approved for use in cosmetic hair products in many regions, including the EU and the US. It is not a natural ingredient and is produced through chemical synthesis.

How it works

In a hair dye product, HC Orange No. 2 molecules are small enough to penetrate the hair cuticle slightly but not deeply into the cortex. They deposit color onto the hair shaft through weak bonds, which is why the color fades gradually with washing. The dye works best on pre-lightened or porous hair because the cuticle is more open, allowing more color to adhere.

Pros

Vibrant color payoff

HC Orange No. 2 delivers a bright, true orange shade that can be mixed with other dyes for custom tones, making it popular for creative hair colors.

Semi-permanent fade-out

Unlike permanent dyes, this ingredient washes out over 4–8 shampoos, so you can change your color without long-term commitment or root regrowth issues.

Cons and cautions

Potential skin irritation

As a synthetic dye, HC Orange No. 2 can cause redness, itching, or burning on the scalp or skin, especially in people with sensitive skin or eczema.

Staining issues

The dye can easily stain skin, towels, and clothing during application, requiring careful use and protective measures like gloves and barrier creams.

Best for

People looking for temporary orange hair color
Those with pre-lightened or porous hair for best color payoff

Use caution if

Individuals with known sensitivity to hair dyes or azo dyes
Pregnant or breastfeeding women seeking extra caution

Usage tips

Always perform a patch test 48 hours before full application to check for allergic reactions.

Apply a thin layer of petroleum jelly or a barrier cream along your hairline and ears to prevent skin staining.

Use gloves and old towels during application to avoid staining surfaces.

Safety summary

HC Orange No. 2 is considered safe for use in hair dyes at typical concentrations when used as directed. However, it can cause allergic reactions in sensitive individuals, and patch testing is strongly recommended. Long-term safety data on repeated scalp exposure is limited, so caution is advised for frequent users.

Research notes

Studies on HC Orange No. 2 are limited. It has been evaluated by the EU Scientific Committee on Consumer Safety (SCCS) and found safe for use in hair dyes at concentrations up to 2%. No significant carcinogenic or mutagenic effects have been reported in available studies, but more independent research is needed.

Common label clues

Typical concentration: 0.1% to 2% in ready-to-use hair dye products
Regulatory status: Approved for use in hair dyes in the EU (CosIng database) and the US (FDA as a color additive for hair dyes). Not permitted in products for skin or nails.
Common uses: Hair dyes, Temporary hair color, Semi-permanent hair color
Environmental note: Synthetic azo dyes can persist in wastewater and may have environmental impacts if not properly treated. Some jurisdictions regulate their discharge.

Good to know

HC Orange No. 2 is often listed alongside other HC dyes in ingredient lists; it's not a single color but part of a blend.
This dye is not approved for use in products intended for the eye area or lips.

Common questions

What is HC Orange No. 2 in beauty products?

What does HC Orange No. 2 do in a beauty product?

Is HC Orange No. 2 safe for most people?

Who should be careful with HC Orange No. 2?

Individuals with known sensitivity to hair dyes or azo dyes Pregnant or breastfeeding women seeking extra caution

Research sources

EU CosIng Database - HC Orange No. 2Open FDA Color Additives for Hair DyesOpen SCCS Opinion on HC Orange No. 2Open

Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.