
Hanna Instruments HI-8004L Foodcare pH 4.01 Buffer Solution - 500ml
Available in convenient, ready-made pH values, the 4.01 pH is a certified value calibration solution with an accuracy of +/- 0.01pH @ 25◦C for use in Water purification plants, the food industry, and anywhere a slightly acidic result is expected. Comes in an FDA compliant bottle.
The pH 4.01 buffer is available in a 500ml bottle, one of the most commonly used buffer solutions. It is extremely stable and represents the mid-way point in the acid range of the pH scale - ideal for those requiring an accurate acid reading, particularly those working in water purification plants, the food industry, and wherever the pH is expected to be acidic.
Buffer solutions should be stored at 25◦C, away from direct sunlight for accurate readings.
To correctly maintain your meter/electrode, we highly recommend use of a Hanna cleaning solution, as well as a buffer, for maximum performance every time. pH4, along with pH7, can also be used as an emergency storage solution.
Hanna buffer solutions are prepared, ready-to-use, according to precise formulas and standardised in accordance with the National Institute of Standards and Technology (NIST) to ensure quality and accuracy. All solutions show a batch number, an expiry date, and the correlation table between pH and temperature. A certificate of analysis is available as standard on FDA bottles.
All bottled solutions are sealed with an air tight, tamper-proof seal to prevent any Carbon Dioxide from entering and causing a change in the pH buffer value.
Specifications
| Accuracy | Standard ±0.01 pH |
| pH Value @25°C | 4.01 |
| Package | FDA Bottles |
| Size | 500mL |
| Quantity | 1 |
| Certificate of Analysis | Yes |

Frequently Asked Questions
Clear answers to help you choose the right water testing solution with confidence
Which brands of water testing kits do you supply?
Do you provide kits for both home and professional use?
Yes — whether you’re a pool or spa owner, aquarium keeper, utility company, or a university laboratory, we have the right solution for your needs.
Can I arrange servicing or calibration for my photometer?
Absolutely. We also provide servicing and calibration to keep your photometers accurate and reliable.
How quickly do you dispatch orders?
Orders placed before 2:30 pm (Monday–Friday) are dispatched the same day. We also ship on Saturdays for your convenience.
Which couriers do you use for delivery?
We deliver through UPS, DPD, and Royal Mail. You can also choose to upgrade to next-day delivery at checkout.
What is your return policy?
We accept returns within 14 days of delivery provided the items are unused, in their original packaging, and in resalable condition. Please contact our team before returning any items.
Can I place bulk or business orders?
Yes, we welcome bulk, trade, and institutional orders. For tailored pricing or large quantities, please get in touch with us directly.
How can I get help if I’m unsure which kit to buy?
You can call us at 📞 +44 (0)115888 2726 and our team will guide you in choosing the most suitable kit for your needs.