Hexavalent chromium
Hexavalent chromium also called chromium VI or 6, is one form of chromium. the metallic, naturally occurring element found in rocks, animals, plants, soil, and volcanic dust and gases. It comes in different forms including trivalent chromium chromium (III), and Hexavalent chromium named as such because it is in the +6 oxidation state, which is is industrially produced.
Hexavalent chromium is listed as a known human carcinogen, causing nasal and sinus cancers, kidney and liver damage, nasal and skin irritation and ulceration, and eye irritation and damage. Exposure can occur through breathing it in, ingesting it in food or water, or direct contact with the skin. Industrial workers who use pigments, spray paints, coatings, plating baths; or weld and cut stainless steel can have higher exposure risks.
Hexavalent chromium, is widely used in electroplating or added to anti corrosion agents in coatings, paints and so on, it is used in the production of stainless steel, in leather tanning, in dyes for textile manufacture and some wood preservatives. It is also used in refrigerant solutions and steel parts that might be found in heat pumps.
Hexavalent chromium is covered by the EU and UK Restriction of Hazardous Substances in Electrical and Electronic Equipment (RoHS) directive and regulations, meaning its use is restricted to 0.1% in products through application and monitored, along with other substances that include lead, cadmium, mercury, polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE), bis(2-ethylhexyl) phthalate (DEHP), butyl benzyl phthalate (BBP), dibutyl phthalate (DBP) and diisobutyl phthalate (DIBP).
In 2023 the EU however revised hexavalent chromium restrictions and published a new RoHS exemption (entry 9(a)-III in Annex III) for hexavalent chromium as an anticorrosion agent in gas absorption heat pumps. It concluded that it is currently scientifically and technically impracticable to replace its usage in these devices. A maximum concentration of 0.7 % hexavalent chromium by weight in the refrigerant solution is considered sufficient which is only valid for gas absorption heat pumps for space and water heating.
[edit] Related articles on Designing Buildings
- Electrical and electronic equipment
- End of life potential.
- Environmental impact assessment EIA.
- Environmental plan for building design and construction.
- Glossary of electrical terms.
- Hire, reclaim and reuse scheme combats construction waste.
- How to conduct a pre-demolition audit.
- Plastic and recycling.
- Primary non-rechargeable batteries.
- Rare earth metals.
- Restriction of Hazardous Substances in Electrical and Electronic Equipment RoHS
- Recycling explained.
- Secondary rechargeable batteries.
- Types of plastic in construction.
- Waste and Resources Action Programme WRAP.
- Waste hierarchy.
- Waste management plan for England.
Featured articles and news
Deputy editor of AT, Tim Fraser, discusses the newly formed society with its current chair, Chris Halligan MCIAT.
Barratt Lo-E passivhaus standard homes planned enmasse
With an initial 728 Lo-E homes across two sites and many more planned for the future.
Government urged to uphold Warm Homes commitment
ECA and industry bodies write to Government concerning its 13.2 billion Warm Homes manifesto commitment.
Places of Worship in Britain and Ireland, 1929-1990. Book review.
The emancipation of women in art.
CIOB Construction Manager of the Year 2025
Just one of the winners at the CIOB Awards 2025.
Call for independent National Grenfell oversight mechanism
MHCLG share findings of Building Safety Inquiry in letter to Secretary of State and Minister for Building Safety.
The Architectural Technology Awards
AT Awards now open for this the sixth decade of CIAT.
50th Golden anniversary ECA Edmundson awards
Deadline for submissions Friday 30 May 2025.
The benefits of precast, off-site foundation systems
Top ten benefits of this notable innovation.
Encouraging individuals to take action saving water at home, work, and in their communities.
Takes a community to support mental health and wellbeing
The why of becoming a Mental Health Instructor explained.
Mental health awareness week 13-18 May
The theme is communities, they can provide a sense of belonging, safety, support in hard times, and a sense purpose.
Mental health support on the rise but workers still struggling
CIOB Understanding Mental Health in the Built Environment 2025 shows.
Design and construction material libraries
Material, sample, product or detail libraries a key component of any architectural design practice.
Construction Products Reform Green Paper and Consultation
Still time to respond as consultation closes on 21 May 2025.
Resilient façade systems for smog reduction in Shanghai
A technical approach using computer simulation and analysis of solar radiation, wind patterns, and ventilation.