'Significant concentration of formaldehyde' enters River Alyn, leaked memo warns

Dead fish in the River Alyn
Dead fish in the River Alyn -Credit:Caroline Dawson, Trustee Welsh Dee Trust

A "significant concentration of formaldehyde" has entered the River Alyn, a leaked memo says. The internal Natural Resources Wales (NRW) report to staff, seen by North Wales Live, raises "significant health and safety concerns" for workers carrying out tasks in the area.

The warning comes after scores of dead fish were found in the river following a devastating fire at the Synthite chemical factory in Mold on Tuesday afternoon. The environmental watchdog is investigating the death of the fish and the wider impact of the devastating fire.

On Wednesday NRW asked people not to go near the River Alyn and to also keep animals away from the water after the incident. Yesterday people spoke of finding dead fish and other wildlife at the River Alyn - which is a tributary of the vital River Dee, a source of drinking water for nearly three million people.

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The memo states: "Please be aware there is a major pollution incident on the River Alyn and on the River Dee. There is a significant concentration of formaldehyde that has entered the River Alyn near Mold."

A previous statement from Synthite on Wednesday said "no chemicals were released during or after the incident, with frequent air monitoring in place". They added: "As the incident was contained to site and no chemicals were released, there was no requirement to sound our siren."

NRW and Synthite have been asked to comment

Formaldehyde is a colourless, strong-smelling, flammable chemical that is produced industrially and used in building materials such as particleboard, plywood, and other pressed-wood products. The chemical is manufactured by Synthite.

It is highly toxic to aquatic life and can be harmful to humans depending on the dose and how people are exposed to the chemical.

The NRW memo advises staff to speak to an area manager before undertaking any work in the area.

It added: "There are significant health and safety concerns related to this incident and we want to ensure the safety of all our colleagues. The impacts from this incident are still being investigated so please check before working in this area.".

Yesterday, Lyndsey Rawlinson from Natural Resources Wales said: “The multi-agency approach continues as we monitor and try to minimise the impact on the community and environment. Officers remain on site as part of the on-going operation.

"We can confirm that around 50 dead fish have been found. Further samples will now be taken from around the site and further downstream to be analysed. We will take any necessary action needed to identify and mitigate any impacts downstream.

“As a precaution, we’re asking people not to go near the River Alyn and to also keep animals away from the water. Multi agencies will continue to work together to minimise the impact on the community and environment.”

Synthite's statement yesterday said: “As North Wales Fire and Rescue Service operations now scale down, we are grateful to all emergency responders for their efforts. We again wish to thank local residents for their patience and sincerely apologise for any inconvenience caused.

“We are continuing to work closely with multiple agencies, including Natural Resources Wales, with this ongoing incident, and activity includes analysing samples of water from the River Alyn. Updates will be provided when further information is available.”

North Wales Police and North Wales Fire and Rescue Service are assisting the Health and Safety Executive with their investigation into the fire.

What UK Government advice says about how exposure to formaldehyde could affect your health

The presence of formaldehyde in the environment does not always lead to exposure. In order for it to cause any adverse health effects, you must come into contact with it. You may be exposed by breathing, eating, or drinking the substance or by skin contact. Following exposure to any chemical, the adverse health effects that you may encounter depend on several factors, including the amount to which you are exposed (dose), the way you are exposed, the duration of exposure, the form of the chemical and if you were exposed to any other chemicals.

Inhalation of formaldehyde can lead to irritation of the nose, mouth and throat. In severe cases, respiratory distress and swelling of the larynx and lungs may occur.

Ingestion of formaldehyde can cause burns and ulcers in the stomach or intestines in the early stages after ingestion. Formaldehyde ingestion may also cause chest or abdominal pain, nausea, vomiting, diarrhoea and gastrointestinal tract haemorrhage. Other clinical features include rapid breathing, yellowish discolouration of the skin, blood in the urine and kidney failure.

Exposure of the eyes to vapour or splashes of formaldehyde causes irritation with immediate stinging and burning with spasm of the eyelids and tearing.

Skin contact with formaldehyde can cause skin irritation and allergic contact dermatitis (allergic response caused by contact with a substance leading to reddening or rash on the skin). Skin contact with high concentrations of formaldehyde solutions can cause blisters and hives.

Formaldehyde and cancer

Formaldehyde has been classified as a cancer causing chemical in humans by the International Agency for Research on Cancer (IARC).

There is evidence that formaldehyde causes nasal tumours (tumours of the nose) and leukaemia in industrial workers exposed over long periods of time (years). However, exposure over short periods of time is unlikely to have the same level of risk.

Vulnerable people

People with breathing problems such as asthma may be more sensitive to the effects of formaldehyde. Individuals who are sensitised to formaldehyde may develop an allergic response (for example allergic contact dermatitis) when they are exposed to formaldehyde.