Plastic Additives in Drinking-Water Contact: EU Positive Lists, NSF/ANSI 61 and KTW in 3 Approval Systems

Entry numbers checked against ECHA CHEM obligation records on 22 September 2026. Regulatory status verified 24 September 2026.

A plastic additive reaches drinking water through a pipe, fitting, tank or seal, and in 2026 three separate systems decide whether it may be there: the European positive list, US certification to NSF/ANSI/CAN 61, and the German KTW assessment basis. From 31 December 2026 the European lists apply under Implementing Decision (EU) 2024/367, so which additives are already on them?

Each system covers its own territory and controls which plastic additives may be present in a material that touches drinking water. The European Union list runs from Directive (EU) 2020/2184 and names a starting substance by entry number; the United States and Canada route runs through certification of the finished compound or component to NSF/ANSI/CAN 61; Germany applies its own national assessment basis, KTW, issued by the Umweltbundesamt, until the European lists take over. Every one of the plastic additives in a pipe, fitting or tank compound is a starting substance in the legal sense, whichever system reviews it.

This page sets out what a positive list is, how the European list applies from 31 December 2026, which of the 39 verified entries already cover common antioxidants, UV stabilizers and PVC stabilizers, how the US NSF/ANSI/CAN 61 route certifies a compound rather than a single additive, what the German KTW assessment basis still requires, which additive package a PVC, PE, PEX or PP-R pipe carries, what is excluded by name, how a drinking-water plastic is tested and what a formulator has to do before the European deadline. This page is a technical reference, not legal advice.

The table below sets the three systems side by side before the article works through each one in turn.

What Is a Drinking-Water Positive List?#

A drinking-water positive list is a list of the starting substances that may be used to make a material in contact with drinking water, each with its own entry number and, where one is set, a maximum use level and a migration value. The European lists cover starting substances, compositions and constituents used in organic materials that touch water intended for human consumption, and each entry that reaches the list has already passed a review of its health effects at the use levels the Decision sets.

A positive-list entry is not a certification of a finished pipe, fitting or tank. It does not replace the mechanical or hygienic product standard the component still has to meet, and a starting substance being listed is not, on its own, an approval of the compound built from it. NSF/ANSI/CAN 61 certification and the KTW assessment basis work at the product level, where the European positive list works at the substance level, and a compound can need all three at once depending on where it is sold.

Which materials and which additives the drinking-water rules cover#

The drinking-water rules apply to the organic material as a whole, so every additive in a pipe, fitting or tank compound falls inside them: antioxidants, UV stabilizers, PVC heat stabilizers, lubricants, fillers and pigments alike. The materials this reference covers are the thermoplastic compounds used to build a drinking-water system:

• Rigid and pressure pipe made from PVC-U, CPVC, PE and PP-R
• Fittings and connectors moulded from the same polymers
• Tanks and storage vessels for drinking water
• Cross-linked polyethylene (PEX) tube for indoor plumbing

The additive functions actually represented in the verified entries on this page span most of a formulator's toolbox: primary and secondary antioxidants, UV absorbers and HALS, organotin PVC stabilizers, a copper halide heat stabilizer, pigments and carbon black, a light diffuser, a cling agent and a chlorinated-paraffin plasticizer.

Seals, gaskets, elastomer components, internal coatings and metal fittings are reviewed under the same three approval systems, but they sit outside this reference, which covers thermoplastic pipe, fitting and tank compounds only.

How drinking-water rules differ from food-contact rules#

A food-contact clearance under Regulation (EU) No 10/2011 does not make an additive usable in a drinking-water pipe: the two regimes list substances separately, number them differently and set different migration values. Three differences separate the regimes in practice. The contact medium differs: food-contact rules cover any food or food simulant, while the drinking-water rules cover only water intended for human consumption. The limit concept differs: food-contact rules set a specific migration limit (SML) in mg/kg and an overall migration limit (OML) in mg/dm², while the drinking-water rules set a maximum use level in the material and a separate migration value into water, MTCtap. Who is listed differs: an additive can hold an FCM number under EU 10/2011 without holding a drinking-water entry number, and the reverse also happens.

Regulation (EU) No 10/2011, also known as EU 10/2011, defines an additive under Article 3(7) as a substance added to achieve a physical or chemical effect during processing or in the finished material, and it clears substances by FCM number under its own Union list. An FCM number under EU 10/2011 is a food-contact clearance, not a drinking-water entry, and the two lists are numbered independently of each other.

Regulation (EU) No 10/2011 is the European food-contact instrument; the United States, China and other jurisdictions run separate food-contact positive lists with their own numbering and their own limits. The food-contact regimes are compared, jurisdiction by jurisdiction, on food contact rules for plastic additives worldwide, which is the reference point for how an FCM clearance in one system compares with a drinking-water entry in this one.

System 1: The European Positive List Under Directive (EU) 2020/2184#

The European positive list for materials in contact with drinking water is established under Directive (EU) 2020/2184 and applies from 31 December 2026, which is the date every additive supplier to the pipe industry is working back from. Commission Implementing Decision (EU) 2024/367 sets out the substances, and each entry that covers a plastic additive carries a four-digit entry number, a review date and, where the Commission has set one, a maximum use level in the material and a migration value in the water. Until 31 December 2026 arrives, a compound producer preparing a drinking-water pipe, fitting or tank still has to keep its national route, NSF/ANSI 61 route or KTW assessment running in parallel, because the European list is not yet the exclusive route.

What the European positive list is and when it applies#

Commission Implementing Decision (EU) 2024/367 sets the European positive lists of starting substances for materials in contact with drinking water, and it applies from 31 December 2026. The Decision was adopted on 23 January 2024 under Directive (EU) 2020/2184, and it lays down rules for authorising the starting substances, compositions and constituents used to manufacture materials and products that come into contact with water intended for human consumption. Before 31 December 2026, national routes such as the German KTW assessment basis, and international certification routes such as NSF/ANSI/CAN 61 in the United States, remain the working compliance path for a European manufacturer as well.

After 31 December 2026, a starting substance that is not on the European positive list cannot be used in a new material for drinking-water contact in the EU, which is why the entry numbers recorded in Table T2 below matter now, well ahead of the date itself.

Which additive families are already on the list: antioxidants, UV stabilizers and PVC stabilizers#

The two standard polyolefin antioxidants are both on the European positive list: Irganox 1010 as entry 0430 and Irgafos 168 as entry 0582, each with a review date of 31 December 2034. Five further antioxidants and one copper-based heat stabilizer are also recorded: Hostanox O3 (entry 0584), P-EPQ (entry 0667), Ethanox 702 (entry 1092), distearyl disulfide (entry 0386) and copper(I) iodide (entry 0349), the last one handled under Annex V of the Decision rather than under a standard use level. Dosage ranges for both primary and secondary antioxidant types are set out on antioxidants for plastics.

Twenty-one entries on the list cover UV stabilizers and HALS, led by Chimassorb 944 (entry 0648), Chimassorb 2020 (entry 0687), Tinuvin 622 (entry 0627), Tinuvin 770 (entry 0969), UV-326 (entry 0406), UV-327 (entry 0405) and UV-P (entry 0381). The 21 listed grades belong to the classes set out on UV stabilizers for plastics, and Table T2 below prints every one of them with its own entry number.

Three organotin compounds used as PVC heat stabilizers hold entries as well: dimethyltin bis(isooctyl mercaptoacetate) (entry 0561), monomethyltin tris(isooctyl mercaptoacetate) (entry 0606) and dioctyltin bis(ethyl maleate) (entry 0007). The two methyltin mercaptoacetate entries carry a review date of 31 December 2028, eight years earlier than the 31 December 2034 review date on the antioxidant entries, which is a planning risk for a tin-stabilized pipe compound rather than a reason for concern about the substance itself. How the tin systems work is covered on PVC heat stabilizers.

Entry numbers, review dates and migration limits#

Each entry on the European positive list carries a four-digit entry number, a review date, and where the Commission set one, a maximum use level in the material and a migration value in the water. The entry number is the identifier used across ECHA CHEM and the Official Journal text, and it stays fixed even when the review date attached to it is later renewed.

A review date marks when the Commission re-examines an entry's terms, not when the entry expires on its own. The two methyltin mercaptoacetate entries, 0561 and 0606, carry a review date of 31 December 2028, while the antioxidant entries 0430 and 0582 run to 31 December 2034; a compound built on the tin stabilizers therefore faces its first regulatory checkpoint six years sooner than one built on the standard antioxidant pair.

A migration value into water, MTCtap, is recorded for one entry in this dataset: carbon black, entry 0348, carries an MTCtap for PAH of 0.1 µg/l alongside its use level. The food-contact equivalent runs through a different unit and a different regime entirely: specific migration limits (SML) of plastic additives are tabulated in mg/kg, not µg/l, and apply under EU 10/2011, not under the drinking-water Decision.

Carbon black, colorants and the only use level in the list#

Carbon black is the one plastic additive in the European drinking-water list with a hard use level: entry 0348 caps it at 2.5 % w/w of the plastic, with benzo[a]pyrene limited to 0.25 mg/kg of the carbon black. The entry also carries the one recorded migration value (MTCtap) in this dataset, 0.1 µg/l for PAH into the water. Grade selection and particle size for carbon black in plastics determine how a given pipe recipe is built up to, but not over, that use level.

Four colour pigments hold recorded entries alongside carbon black: Pigment Black 28 (entry 1225), Pigment Blue 36 (entry 1230), Pigment Orange 13 (entry 1237) and Pigment Red 178 (entry 1240). A fifth pigment, Pigment Red 57:1, also carries an entry, but the entry number could not be confirmed against ECHA CHEM and is not printed here. The pigment classes behind these entries are on colorants for plastics.

Which Plastic Additives Are on the European Positive List? 39 Verified Entries#

The table below lists the 39 plastic additives for which this reference holds a verified European positive-list entry number, with the additive function, the entry, the review date where one is recorded, and the substance record. The rows are grouped by function, in the same order as the rest of this page: antioxidants and heat stabilizers, UV stabilizers and HALS, organotin PVC stabilizers, colorants and carbon black, then the remaining functions.

The European positive list is longer than this table. These are the entries verified against ECHA CHEM obligation records; a substance missing from the table is not necessarily missing from the list.

Footnote 1: Entry numbers from ECHA CHEM obligation records under Directive (EU) 2020/2184; entries 0389, 0627, 0648, 0687, 0706 and 1410 were individually re-verified on 22 September 2026. Footnote 2: Pigment Red 57:1 also carries an entry, but the number could not be confirmed and is therefore not printed.

Each substance links to its full record in the plastic additives database, where dosage, CAS number and the wider regulatory picture for that substance are collected in one place.

System 2: NSF/ANSI/CAN 61, the US Route for a Drinking-Water Compound#

NSF/ANSI/CAN 61 is the North American standard for the health effects of drinking-water system components, and in the plastics chain it is the compound or the finished pipe that is certified to it, not the individual additive. In the United States and Canada, a rigid PVC, PE or PP-R pipe intended for potable water is certified to NSF/ANSI/CAN 61 for health effects and, alongside it, to NSF/ANSI 14 for the plastics piping product itself. PPI TR-2 sits beside both listings as the technical reference for which ingredients, and at what range of levels, an HDB-qualified rigid PVC pressure-pipe compound may contain.

What NSF/ANSI 61 certifies, and what it does not#

NSF/ANSI/CAN 61 certifies the finished component, compound or product that contacts potable water, so an additive supplier cannot hold an NSF 61 certificate for a stabilizer on its own; what exists are stabilizer grades that certified compounds have been built with. A compound producer submits the finished formulation, not a single ingredient, for testing and certification, and the certificate that results covers that formulation as built, in the pipe or fitting it is actually used in.

Suppliers advertise methyltin mercaptide grades as NSF-authorized on their own product literature, which is a supplier statement rather than a certification the ingredient itself carries. A buyer confirms the actual certification at the compound or product level, through the certifier's own listing, not through an ingredient data sheet alone.

Which additives a certified rigid PVC pipe compound contains#

A US rigid PVC pressure-pipe compound is a short recipe: about 100 parts PVC, 0.3 to 1.0 phr of a methyltin or butyltin mercaptide stabilizer, a paraffin and calcium stearate lubricant pair, up to 5 phr calcium carbonate and 0.5 to 3.0 phr titanium dioxide.

Footnote: Range composition from PPI TR-2; wt% = phr of the ingredient divided by the total phr, times 100.

The wt% column above converts each ingredient's phr value by dividing it by the compound's total of 108.03 phr and multiplying by 100; the conversion used in the table is explained in full on PHR (parts per hundred resin). Working in phr rather than wt% is standard for a PVC compound, because it keeps every additive's dose expressed against a fixed 100 parts of resin regardless of how many other ingredients are added.

FDA sets a separate ceiling on the tin stabilizer itself under 21 CFR 178.2010: methyltin stabilizers are capped at 2 wt% in rigid PVC used for food-plant water contact, and reverse-ester methyltin grades are capped at 1.0 % in pipes and 2.0 % in fittings. The FDA caps and the tin SML are covered in full on the methyltin mercaptide record, alongside the compound-level phr range PPI TR-2 sets for the same ingredient.

NSF/ANSI 14 and PPI TR-2: the two listings that sit beside NSF 61#

Three listings decide whether a US water pipe may be sold: NSF/ANSI/CAN 61 for the health effects of the material, NSF/ANSI 14 for the product itself, and PPI TR-2 for whether the ingredients sit inside a qualified range composition. The three listings are described below.

• NSF/ANSI/CAN 61 covers the health effects of the finished component or compound in contact with potable water.
• NSF/ANSI 14 covers certification of the plastics piping product itself, alongside NSF/ANSI 61.
• PPI TR-2 covers the hydrostatic-design-basis range composition that qualifies an ingredient for use in a rigid PVC pressure-pipe compound.

The EU counterparts to this US listing structure are EN 1452 for PVC-U pressure pipe and EN 12201 or ISO 4427 for PE water pipe, which set the product-level requirements a European pipe has to meet in parallel with the positive-list entries for its ingredients.

System 3: KTW, the German Assessment Basis for Plastics in Drinking Water#

KTW is the German assessment basis for plastics and other organic materials in contact with drinking water, issued by the Umweltbundesamt. Until the European positive list applies, national assessment bases such as KTW continue to apply on the German market, and this reference will add the assessment basis's exact title, its binding dates and its annexes once that detail has been verified against primary UBA sources and added to our source library.

Which Additives Go into a Drinking-Water Pipe?#

A drinking-water pipe carries the additive package its polymer needs, and that package is what the positive list and the certification then have to accept: a heat stabilizer, lubricants and fillers in PVC, antioxidants and carbon black in PE, a peroxide or silane system in PEX. Gas, sewer and industrial pipe packages beyond drinking water are covered separately, on additives for plastic pipes, while this section stays inside the drinking-water and potable-water scope for each polymer in turn.

PVC-U and CPVC pressure pipe: the stabilizer, lubricant and filler package#

A drinking-water PVC pipe is stabilized differently on each side of the Atlantic: US pressure pipe uses a methyltin or butyltin mercaptide at 0.3 to 1.0 phr, while EU pipe runs on calcium-based systems, which are 83 % of European stabilizer use. Methyltin mercaptide is the standard primary heat stabilizer for US potable-water, DWV and sewer pipe, and it is one of seven additive line items in the PPI TR-2 pressure-pipe recipe set out earlier on this page. The full formulation guide covering every one of those additives for PVC sets out dosage and selection by function.

EU pipe compounds moved to calcium-based systems after the lead phase-out, and EN 1452 governs the finished PVC-U pressure-pipe product in Europe. One-pack stabilizer choices by pipe type, drinking-water and non-drinking-water alike, are covered on stabilizers for PVC pipes, which sets the calcium-zinc and calcium-organic grades against the US tin-based systems in the same table.

The lubricant pair in both regions works the same way: calcium stearate is the internal lubricant and fusion promoter, and paraffin wax is the external lubricant, together keeping the compound from sticking to processing equipment while it fuses evenly. Why the paraffin and calcium stearate pair works, and how the two lubricant types differ, is set out on processing lubricants for plastics.

Calcium carbonate in a pressure-pipe compound stays inside the PPI TR-2 range of 0 to 5 phr, well below the 15 to 20 % used in non-pressure uPVC drainpipe, because a pressure-rated wall needs the impact and hydrostatic performance a heavily filled compound would compromise. The EU and US recipes for a drinking-water PVC pipe are set side by side on additives for PVC pipe.

PE100 and PE-RT pressure pipe: antioxidants, OIT and carbon black#

A PE100 water pipe is protected by a phenolic antioxidant and a phosphite, and the compound is checked by oxidative induction time, commonly specified at 10 to 20 minutes at 200 to 210 °C. Irganox 1010 (entry 0430) and Irgafos 168 (entry 0582) are the same two antioxidants recorded on the European positive list, so the antioxidant package a PE100 compounder chooses and the one the positive list already covers tend to be the same pair. The full antioxidant and stabilizer package for polyethylene, pipe grade included, is set out on additives for polyethylene.

Carbon black protects PE pipe from UV degradation, and a 35 % carbon black masterbatch let down at 5 to 6.5 % gives about 1.75 to 2.3 % carbon black in the finished pipe, against the 2.5 % w/w cap the European positive list sets on entry 0348. A standard black PE100 pipe recipe therefore lands under the cap, but not by a wide margin, which is why the let-down ratio of the masterbatch is worth re-checking rather than assuming it holds. Method, sample preparation and typical values for oxidative induction time (OIT) are the compound acceptance test referenced above.

Antioxidant in a PE100 pipe is consumed roughly four times faster in 4 ppm chlorine dioxide at 90 °C than in plain chlorinated water, a rate reported by Lancioni and colleagues, Water Research, 2023. No standardised accelerated test exists for that disinfectant attack, so a pressurised loop test that replicates real service conditions remains the closest thing to a standard method for checking how long the antioxidant package actually lasts.

PEX and PP-R: peroxide, silane and copper contact#

PEX pipe is crosslinked either with an organic peroxide, as in PEX-a, or with a silane, as in PEX-b, and the residue of that chemistry is what a drinking-water assessment has to look at. PEX-a mixes HDPE with about 2 % peroxide and crosslinks it at 200 to 250 °C; dicumyl peroxide, the peroxide most often used for this purpose, is harmonised as Repr. 1B and has been on the REACH Candidate List since 27 June 2024. Each PEX grade has to reach a minimum degree of crosslinking, which is what the peroxide or silane dose is set by; how peroxide half-lives and silane crosslinking systems are chosen is set out on crosslinking agents.

PP-R pipe, used for potable plumbing and hydronic heating, takes a phenolic plus thioester long-term thermal stabilization package rather than a peroxide crosslinking system, together with a metal deactivator that protects the polymer where the pipe run touches copper fittings. Copper is a known pro-oxidant for polyolefins, which is exactly the failure mode the metal deactivator in a PP-R compound is chosen to prevent.

What Is Not Allowed in a Drinking-Water Pipe?#

Two exclusions are written into EU law by name: lead stabilizers, and recovered rigid PVC, which may go into the middle layer of a multilayer pipe only when that pipe is not for drinking water. Both exclusions sit outside the positive-list mechanism itself; they come from REACH restrictions and from the pipe product standards, not from the Implementing Decision, and both apply regardless of which of the three approval systems a given pipe is also certified under.

Lead and organotin stabilizers: REACH entries 63 and 20#

Lead has been limited to below 0.1 % by weight of the PVC material since 29 November 2024 under REACH Annex XVII entry 63, and the derogation that still allows 1.5 % lead in recovered rigid PVC until 28 May 2033 explicitly excludes drinking-water pipes and drinking-water fittings. Regulation (EU) 2023/923 sets the entry 63 restriction; the derogation for recovered rigid PVC applies only to listed uses, such as the middle layer of a multilayer non-drinking-water pipe or a non-drinking-water fitting, each marked "Contains ≥ 0,1 % lead". A closed-loop recycling condition applies to that derogation from 28 May 2026, and the Commission reviews the whole derogation by 28 May 2028. Every derogation and deadline in the entry 63 restriction is set out in full on lead in PVC.

Organotin heat stabilizers themselves are not banned from drinking-water pipe. REACH Annex XVII entry 20 restricts named dibutyltin and dioctyltin uses, not the methyltin mercaptides that carry positive-list entries 0561 and 0606, so a tin-stabilized US pressure-pipe compound stays inside both restrictions at once. Which organotin uses entry 20 actually restricts, and which stay outside it, is set out on organotin restrictions.

Recycled plastic in pressure and drinking-water pipe systems#

Recyclate is kept out of pressurised drinking-water and gas pipe systems by the pipe standards themselves, which is why non-pressure sewage and stormwater pipe is where recovered polyolefin and PVC actually go. EN 13476-3 Annex D lists the agreed specification items for PP recyclate used in the outer or middle layer of a multilayer non-pressure pipe: oxidative induction time, ash content, foreign polymers, impurities, pigments and additives, volatile content, tensile properties and traceable origin. How a pipe compound is built to accept recycled content in the first place is covered on design for recycling.

The recovered rigid PVC derogation under REACH entry 63 follows the same logic from the regulatory side: it names the middle layer of a multilayer non-drinking-water pipe as an eligible use and excludes drinking-water pipe and drinking-water fittings by name. The authorisation route recyclers themselves follow is set out on recycled plastics regulations.

How Is a Drinking-Water Plastic Tested?#

A drinking-water plastic is judged on what comes out of it into the water, not on what went into it, so the acceptance tests are migration tests on the finished material plus the compound tests that prove the additive package is intact. The same underlying logic runs through every one of the methods that fall under testing plastic additives across the site: measure what actually transfers into the medium, not only what was formulated into the compound.

Migration into water is measured directly for the one value recorded in this dataset, the carbon black entry's MTCtap of 0.1 µg/l for PAH, which sets what may transfer from the carbon-black-loaded plastic into the water itself. The food-contact equivalent runs a parallel but separate test regime: SML in mg/kg and OML of 10 mg/dm² under EU 10/2011, values that do not apply to a drinking-water migration test even though the underlying principle, migrate then measure, is the same. The nearest standardised procedure most compounders already run is migration testing of plastics for food contact, adapted to the drinking-water medium and duration.

On the compound side, oxidative induction time is the acceptance test that proves an antioxidant package is still active rather than already consumed, commonly specified at 10 to 20 minutes at 200 to 210 °C for a PE100 pressure-pipe compound. A passing OIT result does not itself prove drinking-water suitability; it proves that the stabilizer package the positive list or the NSF certification assumes is actually present at the dose the formulation specifies.

No standardised accelerated test exists for the disinfectant-driven antioxidant consumption that Lancioni and colleagues, Water Research, 2023, measured at roughly four times the normal rate in 4 ppm chlorine dioxide at 90 °C; a pressurised loop test that replicates real service conditions is the closest method available today. What controls the rate at which an additive leaves the polymer in the first place is explained on additive migration in plastics.

What Changes on 31 December 2026, and What to Do Before It#

From 31 December 2026, the European positive lists apply, and a starting substance that is not on them cannot be used in a new material in contact with drinking water in the EU. That date of application, set by Commission Implementing Decision (EU) 2024/367, is the single deadline every additive supplier and compound producer in the pipe industry is working back from, and the review dates already recorded on individual entries, 31 December 2028 for the two methyltin mercaptoacetate entries and 31 December 2034 for the two standard antioxidant entries, are the first checkpoints after it.

A compound producer should work through six steps before the deadline arrives.

1. List every starting substance in the compound, additive by additive.
2. Look each one up in the ECHA CHEM obligation record and note its entry number.
3. Note the review date of each entry and flag everything reviewed in 2028.
4. Check the entries that carry a use level, starting with carbon black at 2.5 % w/w.
5. Re-check the let-down ratio of every masterbatch against that use level.
6. Keep the national route, NSF/ANSI 61 or KTW, running in parallel until it is formally displaced.

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Do Plastic Additives Leach into Drinking Water?#

Yes: measurable amounts of additive-related substances leave plastic pipe into the water, which is exactly what the positive lists and the migration values are built to control. ETBE has been measured leaching from PEX-b pipe at concentrations of 23 to more than 100 µg/L, well above the compound's odour threshold of 5 µg/L, in testing by Durand and Dietrich, Water Science and Technology, 2007. Kelley and colleagues, Water Research, 2014, found 11 PEX-related contaminants across 6 pipe brands, including toluene and 2,4-di-tert-butylphenol.

MTCtap is the control concept the European list uses to keep this kind of leaching inside a set limit, expressed directly as a concentration in the water rather than as a use level in the plastic. Drinking water is one layer of plastic additive regulations as a whole, alongside food contact, toys and recycled content, each with its own migration concept and its own limits.

Whether a specific PVC pipe schedule is safe for drinking water is answered by that pipe's own product certification, such as NSF/ANSI 61, not by the additive chemistry discussed on this page, and this reference does not give product-level advice.

What leaches from PEX and PE pipe: NIAS, degradation products and odour#

The substances measured in water from PEX pipe are mostly not the additives themselves but their reaction and degradation products: 2,4-di-tert-butylphenol, for instance, comes from the breakdown of the phosphite antioxidant Irgafos 168. Durand and Dietrich, Water Science and Technology, 2007, measured ETBE leaching from PEX-b pipe at 23 to more than 100 µg/L against a 5 µg/L odour threshold, a result specific to that study's test conditions rather than current product behaviour across the market. Kelley and colleagues, Water Research, 2014, measured 2,4-di-tert-butylphenol among 11 PEX-related contaminants found across 6 brands in their sampling.

2,4-di-tert-butylphenol is treated as a non-intentionally added substance rather than as an additive in its own right, because it forms during processing or storage rather than being dosed on purpose. How these substances are screened is set out on NIAS: non-intentionally added substances.

Does NSF 61 mean lead free?#

No: NSF/ANSI/CAN 61 evaluates the health effects of everything that can migrate from a drinking-water component, while lead content is handled by a separate standard, so a product can meet one and not the other. For plastics specifically, the European route to the same outcome runs through REACH Annex XVII entry 63, which limits lead to below 0.1 % by weight of the PVC material rather than through NSF/ANSI/CAN 61 itself.

How this page is kept current#

This page is re-checked against ECHA CHEM obligation records whenever an entry reaches its review date, and at least twice a year. The nearest checkpoints are 31 December 2028, when the two methyltin mercaptoacetate entries come up for review, and 31 December 2034, when the standard antioxidant entries do, alongside the 31 December 2026 date of application itself.