Plasticizer Substitution Calculator: 16 Plasticizers Compared at Equal Hardness

This plasticizer substitution calculator converts the plasticizer level of a PVC recipe, in phr, into the level of a replacement plasticizer that gives the same hardness, using typical substitution factors for 16 plasticizers measured against DEHP = 1.00. Replacing 50 phr DEHP with DOTP, for example, needs 51.5 phr DOTP, because DOTP's typical factor is 1.03.

Every result is a starting point for a lab trial, not a final formulation.

What the Plasticizer Substitution Calculator Does#

The calculator answers one formulation question: how many phr of a new plasticizer give the same hardness as the current plasticizer at its current level. Plasticizers are among the highest-volume plastic additives, about 8.4 million tonnes a year according to European Plasticisers, which reports that more than 85 % of them go into flexible PVC. Flexible PVC contains 5 to 65 wt% plasticizer and covers a hardness range of about Shore A 50 to 90, so a change of plasticizer that ignores efficiency moves the product out of its hardness specification.

What you enter#

You enter 3 required values and 2 optional prices.

• Current plasticizer, chosen from the 16 in the factor table
• Current level, in phr (parts per 100 parts of PVC resin)
• Replacement plasticizer
• Price per kg of the current plasticizer (optional)
• Price per kg of the replacement (optional), with a currency label

What the calculator returns#

The calculator returns the replacement level in phr, the change against the current level, the formula with the numbers substituted, a ranked table of all factors and, with prices, the plasticizer cost per 100 parts of resin.

How to Use the Plasticizer Substitution Calculator in 6 Steps#

Substitute a plasticizer in 6 steps: pick the current plasticizer, enter its level, pick the replacement, read the new level, check the REACH badges and, optionally, compare cost.

1. Pick the plasticizer the recipe uses today in "Current plasticizer". The list shows each plasticizer's typical factor next to its name.
2. Enter its level in phr. The calculator opens at 50 phr DEHP, the level the published table uses as its reference.
3. Pick the replacement in "Replacement plasticizer". Use "Swap current and replacement" to run the conversion the other way.
4. Read the replacement level and the formula line below it, which shows both factors and the result.
5. Check the REACH badges of both plasticizers under "Selected plasticizers"; a live profile link opens the full regulatory status.
6. Enter both prices per kg to see plasticizer cost per 100 parts of resin, the difference and the break-even price.

The level in phr is the unit of a PVC recipe; to convert the finished recipe into weight percent or kilograms per batch, use the PHR to weight percent calculator.

The Plasticizer Substitution Formula#

The replacement level equals the current level multiplied by the ratio of the two substitution factors: new phr = old phr × (SF new / SF old). Both factors are expressed against DEHP = 1.00, so the formula works between any 2 plasticizers in the table, not only from DEHP.

A substitution factor (SF) is the amount of a plasticizer that gives the same hardness as 1 part of DEHP. A lower factor means a more efficient plasticizer: DBP at 0.86 needs 14 % less than DEHP, while DTDP at 1.26 needs 26 % more.

Two non-DEHP plasticizers convert the same way. Moving a recipe from 40 phr DINP (SF 1.04) to DOTP (SF 1.03) gives 40 × (1.03 / 1.04) = 39.6 phr DOTP, a reduction of about 1 %. The unit itself and its conversions are explained on PHR (parts per hundred resin).

Worked Example: Replacing 50 phr DEHP in Flexible PVC#

At 50 phr DEHP, the typical replacement levels are 51.5 phr DOTP, 52.0 phr DINP, 55.5 phr DIDP and 55.5 phr TOTM. The table below runs the calculator's default case, 50 phr of DEHP (DOP, dioctyl phthalate), against every plasticizer in the factor table.

Table T1. Replacement levels for 50 phr DEHP, with typical factors and REACH status.

Typical factors from one published efficiency table, DEHP = 1.00. Replacement levels calculated with the formula above. REACH status as recorded in the site's substance records.

The 3 most common DEHP replacements show how small the hardness correction can be. DOTP / DEHT (dioctyl terephthalate), a terephthalate and therefore a non-ortho-phthalate, needs 1.5 phr more (+3 %). DINP needs 2.0 phr more (+4 %), consistent with the near 1:1 substitution of DEHP by DINP in flooring reported by Klotz in 2024. TOTM needs 5.5 phr more (+11 %), the largest correction of the three.

Cost per 100 parts of resin in the worked example#

Plasticizer cost per 100 parts of resin is the level in phr multiplied by the price per kg, which gives the cost per 100 kg of resin. The break-even rule follows directly from the formula: the replacement keeps cost per 100 parts of resin unchanged when its price per kg is at most SF old / SF new times the current price.

• DOTP replacing DEHP breaks even at 50 / 51.5 = 97.1 % of the DEHP price per kg.
• DINP replacing DEHP breaks even at 50 / 52.0 = 96.2 % of the DEHP price per kg.
• TOTM replacing DEHP breaks even at 50 / 55.5 = 90.1 % of the DEHP price per kg.

The calculator stores no prices: enter your own quotes, or compare market levels on plasticizer prices. It compares plasticizer cost only, because cost per kg or per litre of the finished compound also depends on density, fillers and every other ingredient.

Where the Substitution Factors Come From and Their Limits#

All 16 factors are typical values from one published efficiency table, by Kanademy, which compares plasticizers at equal Shore A hardness (about Shore A 80) or at 50 phr, with DEHP = 1.00. They are not supplier data, and the site labels every factor "typical" for that reason. The full background on efficiency is on plasticizer efficiency and substitution factors.

The 5 limits that apply to every result are listed below.

1. One source. The factors come from a single secondary table; a supplier's own factor for a specific grade replaces it.
2. Reference conditions. The real factor depends on the PVC K-value, the filler level and the property you match, so a factor measured under the table's reference conditions is an approximation for any other compound.
3. Low levels. Below about 15 phr, plasticizer can antiplasticize PVC, and a substitution factor does not describe that region; the calculator warns below 15 phr.
4. Other properties. Equal hardness does not mean equal low-temperature flexibility, volatility, migration or fusion behaviour.
5. Test method. Shore hardness is read at 15 s under ISO 868 and ISO 7619-1 and within 1 s under ASTM D2240, so the lab trial states the scale and the reading time; see Shore hardness of plasticized PVC.

Restricted Plasticizers in the Substitution Table#

4 plasticizers in the table, DEHP, DBP, DIBP and BBP, are on the REACH Authorisation List (Annex XIV entries 4, 6, 7 and 5) and restricted under REACH Annex XVII entry 51. Entry 51 limits DEHP, DBP, BBP and DIBP to 0.1 % by weight, individually or combined, in the plasticised material of articles, and it has applied to all articles since 7 Jul 2020 under Commission Regulation (EU) 2018/2005. The Annex XIV sunset date for all 4 was 21 Feb 2015; for DEHP in medical devices, Regulation (EU) 2023/2482 moved it to 1 Jul 2030.

That is why the calculator's badges matter as much as its numbers. DBP is the most efficient plasticizer in the table, but entry 51 rules it out as a substitute in EU articles. The entry 51 scope and exemptions are on REACH Annex XVII restrictions on plastic additives.

DINP and DIDP carry a narrower restriction. Annex XVII entry 52 limits DINP, DIDP and DNOP to 0.1 % only in toys and childcare articles that children can put in the mouth, so DINP is not banned in the EU, and neither DINP, DIDP, DOTP nor TOTM is an SVHC. In the US, the FDA final rule of 20 May 2022 (87 FR 31080) left exactly 8 ortho-phthalates authorised as food-contact plasticizers (DINP, DIDP, DEHP, DCHP, BPBG, DEP, EPEG and DIOP), so DBP, BBP and DIBP are no longer authorised. The badges show REACH only; each profile lists food-contact, US and other rules.

What Changes Besides Hardness When You Substitute a Plasticizer?#

A substitution that matches hardness can still change volatility, permanence, food-contact status and cost, so the plasticizer choice is wider than its factor. Longer alkyl chains are the clearest example: DIDP's C10 chains reduce volatility and improve permanence at the cost of efficiency, consistent with its typical factor of 1.11 against 1.04 for DINP. A side-by-side view of the main grades is on plasticizer comparison.

Food-contact limits differ between replacements#

EU food-contact limits differ by a factor of 100 between DEHP and DOTP. Under Regulation (EU) No 10/2011, DEHP (FCM 283) has a specific migration limit of 0.6 mg/kg since Regulation (EU) 2023/1442, while DOTP (FCM 798) has 60 mg/kg. Which plasticizer families suit which flexible PVC products is set out on plasticizers for PVC.

Non-phthalate options in the table#

Among the plasticizers in the table with a substance record, 5 are not ortho-phthalates: DOTP, DOA, DINA, DIDA and TOTM. DOTP keeps DEHP-like solvation and efficiency with a factor of 1.03, and TOTM is used in wire and cable insulation, automotive interiors and dishwasher gaskets. Other options without a factor in this table, such as DINCH, are covered on non-phthalate plasticizers.

Plasticizer Substitution FAQ#

What is a plasticizer substitution factor?#

A substitution factor is the amount of a plasticizer needed to reach the same hardness as DEHP, written as a ratio with DEHP = 1.00. A factor below 1.00 marks a more efficient plasticizer, and a factor above 1.00 a less efficient one. How each plasticizer family works and where it is used is covered on the hub for plasticizers for plastics.

How much DOTP replaces DEHP?#

DOTP replaces DEHP at 1.03 times the DEHP level, so 50 phr DEHP becomes 51.5 phr DOTP. Confirm the level in a lab trial on your own compound, since K-value and filler shift the real factor.

Is DINP a drop-in replacement for DEHP?#

DINP is close to a drop-in replacement, with a typical factor of 1.04: 50 phr DEHP becomes 52.0 phr DINP. It is not an SVHC, and REACH Annex XVII entry 52 restricts it only in toys and childcare articles that can be placed in the mouth. Its full status is on DINP (diisononyl phthalate).

Which plasticizer in the table is the most efficient?#

DBP has the lowest typical factor, 0.86, but it is on the REACH Authorisation List and restricted under Annex XVII entry 51. DOA, at 0.93, is the most efficient plasticizer in the table with no listing on the SVHC Candidate List, Annex XIV or Annex XVII in the substance records, and DTDP, at 1.26, is the least efficient.

Why does my lab result differ from the calculated level?#

The factors are typical values from one table, while the real factor depends on the PVC K-value, the filler level, the property you match and the hardness test. Use the calculated level as the centre of a short ladder of trial levels and measure hardness with one stated method. For TOTM, the trial starts at 55.5 phr against 50 phr DEHP; its profile is on TOTM (trioctyl trimellitate) plasticizer.

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