Blue MDPE or black PE pipe: colour is not the grade
Updated: October 2026
You are choosing between a blue coil and a black coil. Blue MDPE or black PE pipe is a question about the job and the daylight, not about a stronger plastic. Buried drinking water is identified in blue. Black can be an approved above-ground service pipe, or a garden tube with no approval. The black coils on the [PE pipe comparison](/hub/rods-and-pipes/pe-pipe) are not those service pipes. A purchase through those links can earn a commission, at no extra cost to you.
You are choosing between a blue coil and a black coil. Blue MDPE or black PE pipe is a question about the job and the daylight, not about a stronger plastic. Buried drinking water is identified in blue.
You are choosing between a blue coil and a black coil. Blue MDPE or black PE pipe is a question about the job and the daylight, not about a stronger plastic. Buried drinking water is identified in blue. Black can be an approved above-ground service pipe, or a garden tube with no approval. The black coils on the PE pipe comparison are not those service pipes. A purchase through those links can earn a commission, at no extra cost to you.
Our top picks
| Badge | Product | Colour | Outside diameter | Pressure | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Gardena Gardena connecting pipe 25 mm, 50 m | Black | 25 mm | 6 bar | 8.6 | about £96.95 | View offer |
| Alternative |  B2C B2C black LDPE tube, 16 mm | Black | 16 mm | PN6 | 6.0 | about £36.28 | View offer |
| Alternative |  NONDK NONDK black PE tube, 12 mm | Black | 12 mm | n/a | 1.3 | about £9.09 | View offer |
On this page
Blue for a buried drinking-water service
For a buried pipe carrying water for human consumption, buy blue service pipe, PE80 or PE100 to BS EN 12201, in the outside diameter your water company specifies. The UK national note in BS EN 12201-2, as printed in the BSI preview, says those pipes are blue when buried, for identification, and black above ground for ultraviolet resistance. Blue is how the next person finds the main. It is not a strength grade you buy instead of reading the SDR and the WRAS number.
Polypipe’s PE80 range describes blue 20–63 mm for underground potable services, Kitemarked to BS EN 12201 on that page. A blue coil with no standard and no WRAS number has the colour and not the approval. Water Regs UK still wants 750 mm to 1,350 mm of cover. Black is not the cheap version of the same coil. Diameter comes first on the PE pipe buying guide.
Black when it is a real service pipe
A Kitemarked black PE80 pipe can be the above-ground drinking-water colour. Polypipe says its black 20–63 mm pipe is suitable for potable water above ground and also for non-potable use, and that it is Kitemarked. The condition is the certificate on that product, and use out of the ground, where ultraviolet resistance is the point of the black.
Kalsi and EasyMerchant also say plain black means non-potable. Both descriptions are about different pipes. If the coil is sold as irrigation tube and prints no Kitemark and no WRAS number, do not put it on a kitchen tap. TWI’s note is the check: the pipe should carry maker, material, standard, diameter and SDR or pressure. Colour without those marks is not an approval.
Old alkathene
Black alkathene from the 1960s and 1970s can leave a pencil or woody taste after water has sat in the pipe. Run the cold tap until that standing water is gone. If the taste comes back after the pipe has sat overnight, ask the water company or a WaterSafe plumber to identify it. A photo is not that identification. A new black garden tube shares the colour and not the approval, so it does not replace that old supply.
Black pipe in this comparison
Gardena 2701-20 is black polyethylene, 25 mm in the title, 50 m, with a UV claim and no WRAS number. It is the top pick in this set for a sprinkler main, and the wrong approval for a kitchen tap. Who should buy it is on best PE pipe.
NONDK is black PE, 12 mm outside, 9 mm inside, 1.5 mm wall, £9.09, with no reviews and no standard. B2C is black LDPE, 16 mm, PN6, with no drinking-water line and a length conflict between 50 m and 1 m. UK reviews use B2C as a solid garden connector, not a soaker. Burying either coil does not turn it into blue service pipe.
Yellow and barrier pipe
Yellow polyethylene is gas pipe, and TWI also notes orange for gas. Do not cut either colour, and do not adapt it with a garden fitting. Barrier pipe is the separate product for ground that fuel may have soaked, because ordinary PE can be permeated. Changing blue for black does not add that layer. This page does not describe how to cut or joint yellow pipe.
Common questions
Is blue better quality than black?
No. Blue identifies buried drinking-water pipe. Black can be an approved above-ground service pipe or a garden tube. The marks that matter are the standard, the SDR or pressure, and a WRAS or Kitemark number. A blue coil without those marks is not the better pipe.
Can black MDPE carry drinking water?
Yes, when that pipe is the above-ground potable product and its own page says so. Polypipe’s black PE80 range is described that way and is Kitemarked on that page. The Gardena, NONDK and B2C rows here do not carry that claim. Do not bury an above-ground black service pipe and assume the colour still means potable.
Can blue pipe sit in the sun?
Not as a normal installation. WaterSafe allows blue MDPE above ground only where light cannot reach it and it is protected from warming, freezing and contamination. The BS EN 12201-2 UK note puts black above ground for ultraviolet resistance. Plastic Pipe Shop’s two-to-three-year line is their warning, not a test of one coil.
What is a black pipe with a blue stripe?
Kalsi describes it as a potable product you can tell apart from plain black non-potable pipe. The stripe has to be the maker’s mark, with the stamp of standard, diameter and pressure. Painting a stripe on garden tube does not copy that product.
Why does old black pipe make water taste woody?
Black alkathene from the 1960s and 1970s can leave a pencil or woody taste after water sits in it. The Drinking Water Inspectorate and Anglian Water describe flushing as the way to draw fresher water, and Anglian says the taste is not harmful. Ask the water company to identify the pipe before you replace it.
What colour is gas pipe?
Yellow. Do not cut it or join it to a water fitting. Competence is required under the Gas Safety (Installation and Use) Regulations 1998, and a business has to be Gas Safe registered. If the pipe you have uncovered is yellow, stop and leave the joint. Barrier pipe, not a colour swap, is what contaminated ground needs.
Related pages
Sources
Public sources from the research digest. amazon.co.uk prices are captured shelf prices, not a live crawl on 16 October 2026.
- Water Supply (Water Fittings) Regulations 1999 (retrieved October 2026)
- Water Regs UK: installing pipework (retrieved October 2026)
- Water Regs UK: installing below-ground pipework checklist (retrieved October 2026)
- BPF Pipes Group: specifications for PE pipe, fittings, water supply, drains and sewers (April 2024) (retrieved October 2026)
- WRAS: guide to the materials directory (retrieved October 2026)
- Gas Safety (Installation and Use) Regulations 1998, regulation 3 (retrieved October 2026)
- HSE: gas safety domestic FAQs (retrieved October 2026)
- Screwfix: MDPE pipe (trade blue coil, not an ASIN in this comparison) (retrieved October 2026)
- Kalsi Plastics: blue versus black MDPE pipe (retrieved October 2026)