Most people who own or work on old buildings know to watch for asbestos and lead paint. Far fewer know that the plaster itself can carry a much older hazard. Animal hair mixed into traditional plaster can, in rare cases, carry anthrax. It is an uncommon risk and a highly specialised area, but if you are planning work on a period property it is worth understanding why it comes up and when it matters.
Why anthrax is linked to old buildings
Before modern plasterboard, walls and ceilings were built using lath and plaster. Horsehair, and sometimes cow, ox or goat hair, was mixed into the lime plaster to bind it and stop it cracking. Anthrax is a bacterium that survives for decades as extremely hardy spores. Animal hair imported into the country before controls were tightened could, in a small number of cases, have come from livestock infected with anthrax. The Anthrax Prevention Act came into force in 1919, so the concern is concentrated in buildings plastered before roughly 1900 to 1919.
How real is the risk?
It is important to be measured here. The risk is very low, and plaster that is intact and left undisturbed poses little threat. The concern is disturbance. Sanding, drilling, breaking out or demolishing hair plaster can release spores into the air, which is why the question arises specifically around refurbishment, demolition and construction, not around normal day-to-day occupation of a building.
When an anthrax survey or test is worth considering
The trigger is planned work. If you are refurbishing, demolishing or carrying out major construction on a period building with lath-and-plaster or hair-bound plaster finishes, it is worth assessing. A surveyor visually identifies hair-containing plaster across walls and ceilings, then takes samples following strict guidance on sample size and coverage. A single sample from a multi-room or multi-floor building is not enough for a reliable result. However, for smaller or isolated jobs, such as one damaged wall or an area affected by a water leak, a single spot test can sometimes be used instead of a full survey.
Why this is such a specialised market
This is where anthrax differs sharply from asbestos. The samples cannot be analysed by an ordinary materials laboratory. Analysis is carried out by a specialist government reference laboratory at Porton in Wiltshire, one of very few facilities in the UK equipped to test for anthrax. That scarcity is exactly why anthrax testing is such a niche field, and why very few surveyors deal with it. Because it is so specialised, larger asbestos companies will often bring in a surveyor who handles anthrax specifically to cover the anthrax element of a project. For a property owner or developer, the practical value is having a surveyor who understands the risk, knows when it applies, and can guide you through the right sampling and testing route.
Ready to talk it through?
SE Asbestos Surveys carry out anthrax sampling and hazardous materials surveys across Essex, London and the South. It is specialist work, and something larger asbestos companies bring us in to carry out on their projects as well. Whether you are a property owner or developer planning work on a period building, or a firm that needs the anthrax element of a job covered, get in touch. Call 07872 054963 or visit se-asbestos-surveys.co.uk.
