Testing Plastic Additives and Additive-Dependent Properties: 42 Test Methods in 9 Groups

A plastic additive is worth exactly what it does to a number: an intumescent flame retardant at 22 to 30 wt% lifts the limiting oxygen index of polypropylene from about 17.5 to above 29 vol % O2, and this index holds the 42 test methods that measure effects like that, in 9 groups. Each method guide on this site answers the same four questions in the same order: what the test measures, which standard and edition defines it, what value counts as a pass, and which additive family moves that value. So which number does your additive have to move, and which standard defines it?

The 9 groups are fire and electrical fire safety, thermal and oxidative stability, weathering and light stability, rheology and processing, mechanical and thermo-mechanical properties, surface and film properties, optical and colour properties, composition and identity, and compliance, migration and emissions. Each one answers a question a formulator asks about a family of plastic additives: does the flame retardant package pass, does the antioxidant survive the service temperature, does the slip agent bring friction down far enough to run on a packaging line.

This page defines what it means to test a plastic additive, lists all 42 methods with their current standard edition, matches the 24 additive families to their primary and secondary tests, sets out the package each polymer and application needs, names the 8 bodies that write these standards, explains how to read a result without over-reading it, shows which tests prove regulatory compliance, and closes with a 6-step ordering procedure. The plastic additives database behind this index holds the dosage data these tests are run against.

Table T1. The 9 test groups at a glance

What Does It Mean to Test a Plastic Additive?#

Testing a plastic additive means measuring a property of the compound that the additive is supposed to change, against a control formulation and under a standard that fixes the specimen, the conditions and the pass criterion. A test result is only comparable when the specimen geometry, the moulding route, the temperature or load and the conditioning time are the same in both laboratories, because the standard, not the material, defines the number. Why can the same compound give two different numbers in two laboratories? Usually because one of those four variables was not held fixed, and ASTM D1238 states plainly that melt flow rate is not a fundamental polymer property but an empirically defined parameter that depends on the test conditions written into the method.

The additive changes a number, and the test method defines that number#

Every additive family has one number that proves it works: oxidative induction time for antioxidants, the limiting oxygen index and the UL 94 rating for flame retardants, the coefficient of friction for slip agents, and the heat deflection temperature for fillers and reinforcing fibres. These four pairs repeat across almost every formulation decision on this site, because they translate a chemical function into a number a specification can require.

• Antioxidants are proved by oxidative induction time under ASTM D3895-19 or ISO 11357-6, with polyethylene pressure-pipe compounds specified at 20 minutes or more at 200 or 210 °C.
• Flame retardants are proved first by the limiting oxygen index and UL 94, then by the cone calorimeter: neat polypropylene reaches 1,148 to 1,332 kW/m2 peak heat release, against 220 to 255 kW/m2 with an intumescent system, at 35 kW/m2.
• Slip agents are proved by the coefficient of friction under ASTM D1894-24, commonly targeted at about 0.2 for polyolefin film.
• Fillers and reinforcing fibres are proved by heat deflection temperature: polyamide 6 with 4.7 wt% montmorillonite clay reaches an HDT of 152 °C, 87 °C above the neat polymer, published by Kojima and colleagues at Toyota Central R&D Labs in 1993.

Each of those tests exists because the additive is meant to slow or reverse polymer degradation, whether by oxidation, heat, UV light or mechanical fatigue.

Property tests and composition tests answer different questions#

A property test asks whether the compound performs, and a composition test asks what is actually in it: oxidative induction time says the antioxidant package still works, while liquid chromatography under ASTM D6042-23 says which antioxidant is present and at how many parts per million. The two answers are not interchangeable, and a formulation can pass one while failing the other.

• Property tests measure a functional outcome under fixed conditions, without naming the substance responsible. Oxidative induction time, the limiting oxygen index and the coefficient of friction all belong to this class.
• Composition tests identify and quantify the substances present, independent of whether the compound currently performs. ASTM D6042-23 extracts and quantifies erucamide, vitamin E, Irgafos 168 and Irganox 3114, 1010 and 1076 in polypropylene by liquid chromatography at 200 nm, with a limit of detection near 2 parts per million for phenolic antioxidants, and ASTM D6953-18 runs the same workflow for polyethylene. Ash testing under ASTM D5630-22 quantifies the mineral fraction of a compound but cannot identify which mineral filler is present.

A deformulation run that combines both test types produces the substance list and dosage figures held in the plastic additives database.

Is plastic testing the same as testing a plastic additive?#

No: general plastic testing covers every property of a material, while this index covers only the tests whose result an additive is meant to change, which is why Shore hardness appears here as a plasticizer test and not as a general hardness guide. Plasticizer efficiency is compared at Shore A 80, or at the dosage in phr needed to reach Shore A 80, with DEHP set as the reference substitution factor of 1.00. A tensile test on an unfilled, unmodified polymer, run only to characterise the base resin, sits outside this index for the same reason: no additive moved that number.

42 Plastic Test Methods in 9 Groups#

The 42 plastic test methods in this index fall into 9 groups: fire and electrical fire safety, thermal and oxidative stability, weathering and light stability, rheology and processing, mechanical and thermo-mechanical properties, surface and film properties, optical and colour properties, composition and identity, and compliance, migration and emissions.

1. Fire and electrical fire safety (8 methods)#

Fire tests measure ignition, flame spread, heat release, smoke and electrical tracking, and they decide whether a flame retardant package is finished; the group has 8 methods: the limiting oxygen index, UL 94, the cone calorimeter, the glow wire test, the comparative tracking index, smoke density, the cable fire tests and FMVSS 302. The limiting oxygen index under ASTM D2863-23e1 and ISO 4589-2 is the minimum oxygen concentration, in a flowing oxygen and nitrogen mixture, that just supports flaming combustion. Ordinary air holds about 21 vol % O2, and PVC cable compounds are commonly specified at 26 vol % O2 or above.

UL 94 rates a compound V-0, V-1, V-2, HB, 5VA, 5VB or, for foam, HF-1/HF-2, on a 125 by 13 mm specimen at a stated thickness, using a 20 mm, 50 W flame applied twice for 10 seconds: V-0 requires each afterflame of 10 seconds or less, 50 seconds or less in total, and no ignition of the cotton indicator, while V-2 allows flaming drips that do ignite that cotton. A rating is valid only at the thickness tested and is listed on the manufacturer's UL Yellow Card, harmonised internationally as IEC 60695-11-10 and -11-20. The cone calorimeter, standardised as ISO 5660-1 and ASTM E1354-26, burns a specimen under a radiant heat flux of 35 or 50 kW/m2 and calculates heat release from oxygen consumption, using the Huggett constant of about 13.1 MJ per kilogram of oxygen consumed; Vytenis Babrauskas built the instrument at the National Bureau of Standards in 1982. Neat polypropylene reaches a peak heat release rate of 1,148 to 1,332 kW/m2, against 220 to 255 kW/m2 for the same polymer with an intumescent system at 35 kW/m2.

The glow wire test under IEC 60695-2-11, -2-12 and -2-13 applies a heated wire for 30 seconds; IEC 60335-1 clause 30.2.3 requires a flammability index of 850 °C or more and an ignition temperature of 775 °C or more, or a 750 °C test with flaming of 2 seconds or less. The comparative tracking index under IEC 60112 reports the voltage, up to 600 V, that a material withstands before electrical tracking starts: neat polyamide 6 reaches 600 V and falls to 550 V once 15 % of an aluminium diethylphosphinate system is added. Smoke density under ASTM E662 and ISO 5659-2 reports the specific optical density, cable fire performance is classified under the EU Construction Products Regulation as Euroclasses Aca to Fca (EN 50399, EN 61034 for smoke, EN 60754-2 for acidity), and FMVSS 302 (49 CFR 571.302; ISO 3795) requires a horizontal burning rate of 102 mm/min or less on a specimen up to 13 mm thick.

2. Thermal and oxidative stability (4 methods)#

Thermal and oxidative stability tests measure how long a compound survives heat and oxygen, and they are the proof of an antioxidant, an acid scavenger or a PVC heat stabilizer; the group has 4 methods: oxidative induction time, long-term heat aging, differential scanning calorimetry and PVC heat stability testing. Oxidative induction time under ASTM D3895-19 and ISO 11357-6 holds a specimen isothermally at 190 to 220 °C and switches the atmosphere from nitrogen to oxygen, timing the onset of exothermic degradation; polyethylene pressure-pipe compounds are specified at 20 minutes or more, measured at 200 or 210 °C depending on the specification, and the high-pressure variant under ASTM D5885 runs at 3.4 MPa oxygen and 150 °C. ASTM D3895 calls the result a qualitative assessment of stabilisation and warns that a volatile antioxidant can give a poor result while still performing adequately in service.

Long-term heat aging under ASTM D3012-19 and the UL 746B relative thermal index measure days to embrittlement: recycled polypropylene at 150 °C embrittles after about 25 days unstabilised, against 37 to 42 days with 0.2 to 0.4 % of a stabiliser blend added. The same differential scanning calorimetry run used for melting behaviour gives the crystallisation temperature that ranks nucleating agents against each other. PVC heat stability testing, the Congo red method under ISO 182-1, holds a specimen at 180 °C (some laboratories at 200 °C) and times the release of hydrogen chloride to an end point near pH 3; thermogravimetric analysis is not sensitive enough for this early stage, and a dynamic version runs the same principle in a torque rheometer.

3. Weathering and light stability (2 methods)#

Weathering tests expose a compound to filtered xenon or fluorescent UV light with heat and water in a fixed cycle, and they rank UV absorbers, hindered amine light stabilizers and pigments against each other; the group has 2 methods: accelerated weathering and the carbonyl index. Xenon-arc weathering under ISO 4892-2 and ASTM G155-25 runs Method A cycle 1 as 102 minutes of light followed by 18 minutes of light with a water spray, at 0.51 W/(m2·nm) at 340 nm and a black-standard temperature of 65 ± 3 °C. Fluorescent-UV weathering under ISO 4892-3, ASTM G154-23 and ASTM D4329-26 commonly runs cycle 4: UVA-340 lamps at 1.55 W/m2, 8 hours of UV at 70 °C followed by 4 hours of condensation at 50 °C. Neither method simulates atmospheric pollution, biological attack or salt water, and ASTM G155 recommends two control materials per batch, because no universal factor converts laboratory hours into outdoor service years.

Endpoints read from a weathering run are colour difference, yellowness, gloss retention, the point where elongation at break falls to 50 % of its initial value, and the carbonyl index, from the FTIR band near 1715 cm-1 that grows as the polymer backbone oxidises.

4. Rheology, processing and network structure (4 methods)#

Rheology tests measure how the melt flows and how far the polymer chains have been built up or broken down, and they are how lubricants, processing aids, peroxides and chain extenders are judged; the group has 4 methods: melt flow rate, intrinsic viscosity, PVC fusion testing and the gel content and hot set tests. Melt flow rate under ISO 1133-1 and -2 and ASTM D1238-26 extrudes the melt through an 8.000 by 2.095 mm die, polypropylene at 230 °C / 2.16 kg and polyethylene at 190 °C / 2.16 kg, reported in g/10 min (MVR in cm3/10 min); both standards call the result empirical, not fundamental, and antioxidant performance in processing is commonly read as melt-flow retention across repeated extrusion passes.

Intrinsic viscosity, under ASTM D4603 and ISO 1628-5, is the chain-extender metric for PET and recycled PET, since a chain extender rebuilds molecular weight lost during recycling. PVC fusion testing runs the compound in a torque rheometer and reports a fusion time and a stability time; no verified ASTM designation exists for the method in this reference, so it is described by principle and instrument only. Gel content and hot set testing measure the degree of crosslinking in crosslinked polyethylene (XLPE) and PEX pipe, gel content from the insoluble fraction after solvent extraction and hot set from elongation under load at temperature; no verified standard number or target percentage is available in our source library.

5. Mechanical and thermo-mechanical properties (6 methods)#

Mechanical tests measure stiffness, toughness, hardness and how much heat the part takes under load, and every filler, reinforcing fibre, impact modifier and plasticizer is bought on them; the group has 6 methods: heat deflection temperature, the Vicat softening point, impact strength, tensile testing, Shore hardness and thermal conductivity. Heat deflection temperature under ASTM D648-18 (edgewise, 3 mm and thicker) and ISO 75-1/-2 (flatwise, 80 by 10 by 4 mm bars) applies 0.455, 1.82 or 8.00 MPa and heats the specimen at 2 °C/min to 0.25 mm deflection; ASTM D648 warns the data are not intended for design or for predicting endurance at elevated temperature. Polyamide 6 with 4.7 wt% montmorillonite reaches an HDT of 152 °C, 87 °C above the neat polymer.

The Vicat softening point under ISO 306 and ASTM D1525-25 presses a 1 mm2 indenter to a 1 mm penetration, at 10 N (method A) or 50 N (method B) and 50 or 120 °C/h; ISO 10350 standardises on B50, and D1525 is not recommended for non-rigid PVC. CPVC reaches Vicat B 106 to 115 °C. Impact strength is reported as Izod under ASTM D256-26 in J/m on a 63.5 by 12.7 by 3.2 mm notched bar, or as Izod and Charpy under ISO 180 and ISO 179 in kJ/m2: recycled PET with glass fibre and an ethylene copolymer impact modifier rises from 5.2 to about 8.1 kJ/m2 by ISO 180. Izod is named for Edwin Gilbert Izod (1903) and Charpy for Georges Charpy (1901).

Tensile testing under ISO 527-1/-2 and ASTM D638-22 covers specimens up to 14 mm thick, while ASTM D882 covers film below 1 mm; retention of elongation at break after ageing is the standard ageing endpoint. Shore hardness, read at 15 seconds under ISO 868/ISO 7619-1 or within 1 second under ASTM D2240 (12 durometer types), needs a specimen at least 6 mm thick, and readings below 10 or above 90 are unreliable. Flexible PVC sits at 50 to 90 Shore A, and plasticizer efficiency is compared at Shore A 80, or at 50 phr, against DEHP set to a reference substitution factor of 1.00. Thermal conductivity has no verified standard number or W/(m·K) value in our source library; it is named here as the property conductive fillers are chosen to raise, with no figure published on this page.

6. Surface, film and electrostatic properties (5 methods)#

Surface tests measure what happens at the boundary of the plastic, where slip agents, antiblock minerals, antistatic agents, antifog surfactants and anti-scratch additives do their work; the group has 5 methods: the coefficient of friction and blocking, surface resistivity, static decay, antifog testing and scratch resistance. The coefficient of friction under ASTM D1894-24 and ISO 8295 is read film-on-film or film-on-metal, static and kinetic; the standard notes that slip additives bloom to the surface over time, so the result depends on how long ago the film was extruded, with erucamide reaching most of its friction drop within 24 to 48 hours and its final value after 7 to 10 days, commonly targeted at about 0.2 for polyolefin film. Blocking, under ASTM D3354-21, reports the load needed to separate 100 cm2 of film-to-film contact, capped at 200 g.

Surface resistivity under ASTM D257 (not for moderately conductive materials) and IEC 62631-3-2 changes rapidly with humidity, so conditioning is part of the method. Antistatic plastics sit at 1e9 to 1e13 ohm, insulative above 1e14 ohm, and untreated PE and PP at 1e15 to 1e16 ohm; a permanent antistatic additive at 20 wt% in PP gives 3.64e11 ohm on day 0, falling to 4.69e10 ohm by day 60. Static decay, under FTMS 101C method 4046, EIA-541 and IEC 61340, times how long a charge takes to dissipate. Antifog performance is judged by hot-fog and cold-fog practice and drip duration, with no verified standard designation in our source library. Scratch resistance uses OEM-specific methods, including PV 3952, GMW 14688 and crosshatch testing, named here without quoted pass criteria.

7. Optical, colour and dispersion (4 methods)#

Optical tests measure how much light the plastic scatters and how far its colour has drifted, and they settle arguments about clarifying agents, pigments, masterbatch and dispersing aids; the group has 4 methods: haze and clarity, the yellowness index, colour measurement and dispersion testing. Haze under ASTM D1003-21 is read by procedure A with a hazemeter or procedure B with a spectrophotometer, with procedure A values normally slightly higher and less variable; above 30 % haze a material is classed as diffusing and testing moves to ASTM E2387 instead. A sorbitol-based clarifier such as DMDBS is effective at 0.2 to 1 wt% and lowers haze accordingly.

Yellowness index is reported under ASTM E313-20, reapproved 2025, and is valid for materials with a dominant wavelength of 570 to 580 nm; ASTM D1925, its predecessor, was withdrawn in 1995 and must never be cited as current, even though some data sheets still quote it. Colour difference is reported under ASTM D2244-25, most commonly as CIELAB Delta E. Pigment and masterbatch dispersion quality is reported as a filter pressure value in bar per gram of pigment under the EN 13900 series, and agglomerate grading for carbon black in polyolefin pipe follows ISO 18553.

8. Composition and identity (3 methods)#

Composition tests answer which additive is in the compound and how much, and they are how an incoming lot, a competitor sample or a failed part is deformulated; the group has 3 methods: additive analysis, ash content and fibre length and glass content measurement. A deformulation workflow typically screens with FTIR and thermogravimetry, then separates by liquid or gas chromatography with mass spectrometry, using pyrolysis GC-MS for polymeric additives and ICP or XRF for elements. ASTM D6042-23 covers polypropylene and ASTM D6953-18 covers polyethylene. In 2026, Erisman and colleagues at the National Institute of Standards and Technology published a free pyrolysis GC-MS search library for polymer and additive identification in Environmental Science & Technology.

Ash content under ASTM D5630-22 (procedure A, 5 to 50 g in a muffle furnace; procedure B, a 2 to 10 g rapid ash; halogenated polymers excluded) and ISO 3451 quantifies the mineral fraction but does not identify it, since calcium carbonate decomposes above about 600 °C while aluminium trihydroxide and magnesium hydroxide lose bound water instead. Carbon black content follows ASTM D1603-20 and ISO 6964, and polyethylene pressure pipe is specified at 2.0 to 2.5 wt% carbon black. Fibre length and glass content in reinforced compounds are measured after removing the resin by ashing or ignition loss.

9. Compliance, migration and emissions (6 methods)#

Compliance tests measure what leaves the plastic and compare it with a legal limit, and they apply to every additive in a food-contact, packaging, electronics, toy or automotive article; the group has 6 methods: migration testing, PFAS testing, phthalate testing, RoHS screening, fogging and VOC testing, and odour testing. Migration testing under Regulation (EU) No 10/2011 checks a compound against an overall migration limit of 10 mg/dm2 (60 mg/kg for infant articles), using simulants A to E and conditions OM0 to OM9; EN 1186 covers overall migration and EN 13130 covers specific migration of a named substance. PFAS testing, run as targeted LC-MS/MS plus a total-fluorine screen, checks food-contact packaging against the PPWR, Regulation (EU) 2025/40, which applies from 12 August 2026 and limits any single PFAS to 25 ppb, the sum of targeted PFAS to 250 ppb and total PFAS, including polymeric PFAS, to 50 mg/kg.

Phthalate testing, under CPSC-CH-C1001-09.4, EN 14372 and IEC 62321-8, checks a plasticizer against REACH Annex XVII entry 51, which has limited DEHP, DBP, BBP and DIBP to 0.1 % in all articles since 7 July 2020. RoHS screening, using the IEC 62321 series with XRF as the initial step, checks four restricted phthalates plus PBB and PBDE against the 0.1 % threshold set by Directive 2011/65/EU as amended by (EU) 2015/863. Fogging and VOC testing under DIN 75201 and VDA 278 desorb a sample at 90 °C for 30 minutes and quantify the result as toluene equivalents, while odour testing under VDA 270 grades a sample after 2 hours at 80 °C on a 1 to 6 scale; low-molecular-weight phenolics such as BHT are a known source of both elevated VOC and elevated odour.

Complete List of Plastic Test Methods: All 42 Guides#

The complete list below gives all 42 plastic test methods with their group, what they measure, the standard and current edition, the unit or class reported, and the additive families that move the number.

Table T2. All 42 plastic test methods

One test guide that measures an additive effect sits outside this cluster: antimicrobial plastics testing under ISO 22196, JIS Z 2801 and ISO 7581 lives inside the antimicrobial additive family instead of this index, because it tests a single functional claim rather than a property class shared across families.

Which Test for Which Additive? The Additive and Test Matrix#

Each additive family is proved by one primary test and checked by two or three secondary ones: antioxidants by oxidative induction time, then by melt-flow retention and yellowness over repeated extrusion passes, and flame retardants by UL 94, then by the limiting oxygen index and the cone calorimeter. The table below carries that logic across all 24 families covered by this reference.

Table T3. Additive family and test matrix

Which Tests Each Polymer and Application Needs#

The test package follows the polymer and the end use: a polyethylene pressure-pipe compound is judged on oxidative induction time, carbon black content and dispersion, a polyolefin film on friction, blocking and haze, and an automotive interior part on fogging, emissions and odour. Additives by polymer sets out the full formulation guide behind each row; this table gives only the tests that decide whether the package passes.

Table T4. Test packages by polymer and application

Who Writes These Standards, and Which Edition Applies#

The 42 methods come from 8 standards bodies: ASTM committees D20 and E05, ISO technical committee 61, IEC technical committee 89, UL Solutions, CEN technical committee 194, the German automotive association VDA, SAE International and the Geosynthetic Institute. Each body owns a different slice of the test network: ASTM and ISO cover general plastics and fire behaviour, IEC and UL own electrical fire hazard and certification, CEN owns the EU food-contact migration methods, VDA and SAE own automotive-specific procedures, and the Geosynthetic Institute owns the GRI-GM13 specification used for geomembrane oxidative stability.

Table T5. Standards bodies, scope and current editions

Never present an ASTM method and its ISO counterpart as interchangeable: ASTM D1238-26 and ISO 1133-1 measure the same property under different technical requirements, and the same caveat applies to ASTM D638 against ISO 527 and to ASTM D2565 against ISO 4892-2. Thirteen of the ASTM editions indexed on this page were reissued between 2024 and 2026, among them D256-26, D1238-26, D4329-26, D7309-26a, E1354-26, G155-25, D1525-25, D1894-24, D2244-25, E313-20 (reapproved 2025), D1003-21, D5630-22 and D6042-23. ASTM D1925, once the standard for yellowness index, was withdrawn in 1995 and still appears on legacy data sheets even though it should never be cited as current. For tensile testing specifically, ASTM D638 above 1 mm and ASTM D882 for film below 1 mm answer "What is the ASTM standard for tensile testing of plastics?" and the full method, with its target values, is covered on the dedicated tensile testing guide.

How to Read a Test Result Without Over-Reading It#

A plastic test result is valid for the specimen, the thickness and the conditions written on the report, and three of the numbers quoted most often in additive selection say so in their own standards. ASTM D3895 calls oxidative induction time a qualitative assessment of the level of stabilisation, and the PE100+ Association reports no good correlation between OIT and brittle failure of medium-density PE pipe in service. ASTM D1238 calls melt flow rate empirical rather than fundamental. ASTM D648 states that heat deflection temperature data are not intended for design or for predicting endurance at elevated temperature. A result that passes all three tests still says nothing about fire hazard in a real building, service life in a real installation, or legal status in a given market.

Ranking tests are not fire hazard or service life#

The limiting oxygen index ranks materials in a laboratory flow tube and says nothing about the hazard of a real fire, which is why a V-2 compound that drips can carry a higher oxygen index than a V-0 compound that does not. LOI is a small-scale ranking tool, sensitive to dripping and to specimen geometry, so it ranks materials differently from UL 94 whenever dripping is involved, because the V-2 rating specifically allows flaming drips that a V-0 rating does not. Cone calorimeter data need the same caution: Bernhard Schartel of the Bundesanstalt für Materialforschung (BAM) in Berlin and T. Richard Hull of the University of Central Lancashire published the standard interpretation of cone calorimeter results in a 2007 paper in the journal Fire and Materials, warning against reading a single heat-release number as a stand-alone hazard score. Weathering carries the same limit: no universal factor converts laboratory exposure hours into outdoor service years.

The conditions are part of the result#

A melt flow rate without its temperature and load is not a result, and neither is a heat deflection temperature without its stress or a cone peak heat release rate without its heat flux. Melt flow rate is meaningless without its condition: 230 °C and 2.16 kg for polypropylene, 190 °C and 2.16 kg for polyethylene. Heat deflection temperature at 0.455 MPa and at 1.82 MPa are two different numbers on the same specimen, and Vicat B50 is the ISO 10350 convention rather than the only valid combination. Cone calorimeter results depend on whether the heat flux was set to 35 kW/m2, representing a developing fire, or 50 kW/m2, representing a more severe exposure typical of engineering-plastics testing. Surface resistance changes rapidly with humidity, so the conditioning step is as much a part of the result as the final ohm reading, and mismatched conditions are a common source of additive-related defects when two laboratories disagree on a repeat measurement.

Specimen history: thickness, conditioning and blooming#

Three properties of the specimen decide whether two laboratories agree: its thickness, its conditioning and how long ago it was made. A UL 94 rating is valid only at the thickness actually tested, and specimens are conditioned for 48 hours at 23 °C and 50 % relative humidity, plus a further 7 days at 70 °C, before the flame is applied. ASTM D1894 notes that slip additives bloom to the surface of a film over time, so a coefficient-of-friction result depends on how long the specimen has sat since extrusion, with most of the friction drop occurring in the first 24 to 48 hours and the final value reached only after 7 to 10 days; a film tested too early can look like a slip-agent failure that resolves itself within a week. Shore hardness readings below 10 or above 90 on a given scale are unreliable and call for a different scale entirely, and ISO 868 fixes the reading at 15 seconds after the indenter contacts the specimen. Blooming behaviour itself, and how it interacts with other surface additives, belongs to the formulation cluster rather than to this index.

Which Tests Prove Regulatory Compliance?#

A compliance claim is only as good as the test behind it: the overall migration limit of 10 mg/dm2 in Regulation (EU) No 10/2011 is proved by an EN 1186 test in the right simulant under the right time and temperature condition, and nothing else proves it. Plastic additive regulations sets the limits; this table lists only the test that proves compliance with each one.

Table T6. Which test proves which compliance claim

Food contact: EU 10/2011 overall and specific migration, and FDA extraction#

Overall migration under EU 10/2011 is tested with simulant A (ethanol 10 %), simulant B (acetic acid 3 %, for foods below pH 4.5), simulant C (ethanol 20 %), simulant D1 (ethanol 50 %), simulant D2 (vegetable oil) and simulant E, Tenax, for dry foods, under conditions from OM0 (30 minutes at 40 °C) to OM7 (2 hours at 175 °C). A hot-fill rule sets the test time as t = 120 / 2^((T-70)/10) minutes for 70 to 100 °C, converted using the standard 6 dm2 per kg convention; a fat reduction factor of (% fat x 5)/100 applies to fatty foods, except infant food. Repeated-use articles are tested three times and judged on the third, with migration not allowed to increase; Regulation (EU) 2025/351 formalised those criteria under EU 10/2011, and the sell-through period for old-rule products placed on the market before 16 September 2026 has now ended.

The United States has no equivalent overall migration limit. Instead, resin-specific extractable fractions are cleared under specific 21 CFR sections, for example the n-hexane extractable fraction under 21 CFR 177.1520 and the conditions of use A through H in 21 CFR 176.170 Table 2. A substance covered this way is cleared under its 21 CFR section or the subject of an effective food contact notification; it is never accurate to write that the FDA food contact rules "approve" an additive. Additive migration in service depends on the same simulant chemistry but runs over the article's real contact time and temperature.

Packaging, electronics and toys: PPWR PFAS limits, RoHS and phthalates#

Food-contact packaging is tested for PFAS against the PPWR, which applies from 12 August 2026 and sets three thresholds: 25 ppb for any single targeted PFAS, 250 ppb for the sum of targeted PFAS, and 50 mg/kg for total PFAS, including polymeric PFAS. Where total fluorine testing shows a result above 50 mg/kg, the supplier must show, on request, how much of that fluorine comes from PFAS rather than from another source under the PPWR. The additive directly affected by this threshold is the fluoropolymer processing aid used in polyethylene film, which is why PFAS-free processing aids exist as a formulation option. The wider EU restriction on PFAS as a class remains pending at the European Chemicals Agency, so it is not accurate to write that PFAS are banned in plastics; only the PPWR's food-contact-packaging limits are currently in force.

RoHS restricts DEHP, BBP, DBP and DIBP, plus PBB and PBDE, to 0.1 % each, screened first by XRF and confirmed by RoHS and plastic additives test methods in the IEC 62321 series. Toys and childcare articles are tested for phthalates under CPSC-CH-C1001-09.4 and EN 14372, against REACH Annex XVII restrictions entry 51, which has limited DEHP, DBP, BBP and DIBP to 0.1 % combined in all articles since 7 July 2020.

How to Order a Test: Specimen, Conditions and What to Specify#

Specify a plastic additive test in 6 steps: name the claim, pick the method, fix the conditions, state the specimen, send a control, and ask for the raw data. Each step closes off a way a result can come back ambiguous.

1. Name the property and the specific additive claim the test has to prove, not just the additive family.
2. Pick the method with its exact designation and current edition, for example ISO 4589-2 rather than "the oxygen index test".
3. Fix the conditions: temperature, load, heat flux, weathering cycle or migration simulant, matched to the end use.
4. State the specimen: geometry, thickness, moulding route (specimens are commonly moulded to ASTM D4703-24) and conditioning time, since plastic compounding conditions change the result as much as the additive does.
5. Send a control formulation, without the additive under test, alongside the trial batch.
6. Ask for the raw conditions on the test report, not only the pass or fail rating.

This reference runs no laboratory, sells no testing and takes no payment for placement anywhere on this page, so the choice of which laboratory to use is the reader's own, guided by how to select plastic additives for the formulation decision that the test result will confirm.

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What a Test Cannot Tell You About an Additive#

A test measures what a compound does under one set of conditions; it does not tell you whether the additive is legal in your market, whether it will still be legal next year, or how it behaves in a fire, a landfill or a recycling line. A volatile antioxidant can give a poor oxidative induction time result and still perform adequately in service, exactly as ASTM D3895 itself warns. Laboratory weathering does not simulate atmospheric pollution, biological attack or salt water, so a xenon-arc result is a ranking tool, not a service-life prediction. The regulatory status of a substance comes from the regulation itself, never from a property test: passing a mechanical or optical test says nothing about whether an additive appears on the REACH Candidate List or a national restriction. Design for recycling depends on additive identity and dosage information that a property test does not report, and the long-term behaviour of additives already built into legacy plastics sits in a different part of this reference entirely.

Tests and properties this reference does not cover#

This index covers the tests an additive is meant to move, so 6 common searches sit outside it. The following topics belong elsewhere and are named here only so the reader is not left searching this page for them:

• Resin identification codes and "which plastic number is safe" questions belong to general polymer science, not additive testing.
• Consumer or at-home microplastic detection is a separate, non-laboratory topic.
• Plastic processing techniques, such as injection moulding, extrusion, blow moulding and thermoforming, are process operations rather than test methods.
• General mechanical characterisation of unfilled, unmodified polymers sits outside this index, since no additive moved the number.
• Biological, medical and pharmaceutical device testing follows its own regulatory framework, separate from plastic additive testing.
• Testing of paints, coatings, adhesives and rubber compounds is covered by their own standards bodies and is out of scope for a plastic additives glossary built around plastics only.

How the standard editions on this page are kept current#

Every standard number and current edition on this page was verified on 22 September 2026, and the page is re-checked every January and June on a fixed schedule. An out-of-cycle update is triggered by a new ASTM or ISO edition being issued, by a regulatory change such as the PPWR PFAS limits taking effect, or by a withdrawal such as that of ASTM D1925. Several ISO and IEC texts are paywalled, so any clause-level figure that could not be verified directly against the source standard is marked as such on the relevant child page rather than stated here as settled fact. This page's editorial policy sets out that verification process in full.

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