LM Wind Power is the biggest manufacturer of wind turbine blades in the world. It has factories globally, including in Denmark, the US and China. A series of allegations by former employees about various illnesses has forced government authorities in Denmark to investigate practices at the company's Danish factories.
The report, by the National Board of Industrial Injuries and the Danish Working Environment Authority, was published in March. It focuses on LM Wind Power at 13 different locations across Denmark and the use of styrene in wind turbine production between 2000 and 2010.
LM Wind Power uses polyester and glass fibre in its blades. Styrene is a solvent that is released during the blade-hardening process.
During this period, the company had been issued with 52 official notifications from the Danish Working Environment Authority relating to chemical health impacts associated with polyester casting of blades. LM Wind Power has also been fined a total DKK 232,500 (EUR31,178) for styrene-related violations of the Work Environment Act.
One of the complainants, 48-year old Lajla Wilkenskjeld, worked for LM Wind Power in Hammelev between 2000 and 2009. The first four years she worked on the production line where styrene was used in the treatment of rotor blades.
"I followed the safety rules in the factory. But after some time I became ill with nausea, diarrhoea and a very bad headache," Wilkenskjeld says. She believes that this was caused by exposure to styrene while she was working at LM Wind Power.
After complaining to management, she was moved to another department. Today she works for another company but still suffers from eczema and stomach problems. But her greatest worries are the future and the risk of cancer.
The report cites World Health Organisation reports classifying styrene as a suspected carcinogen. But it says that it does not expect LM Wind Power employees to experience a significant number of long-term health problems - such as cancer or brain damage - associated with exposure to styrene. But it does add: "This view may change if hitherto unnotified cases come to light."
Wilkenskjeld has reported her case to the National Board of Industrial Injuries, which has established a task force to examine the reported injuries. Since February, it has received over 80 cases.
LM Wind Power had serious and recurring problems with its work environment, according to employment minister Inger Stojberg. The company should have taken more radical measures as the same type of problems were occuring year after year, she says. She also questions whether the authorities took all necessary measures, and believes that they should have been tougher with LM.
There are alternatives to the use of styrene in wind turbine blade production. Danish firm Vestas, the world's largest wind turbine manufacturer, stopped using polyester in wing manufacturing in the mid-nineties - and thus the solvent styrene. Instead, it uses epoxy as a binder, which gives blades strength and flexibility. However, questions have also been raised over the health effects of epoxy.
LM Wind Power's spokeswoman Helle Larsen Andersen says that the company is collaborating with the Danish regulatory authorities to review the allegations from past employees over styrene.
"LM Wind Power does not recognise the picture of the company portrayed by them. However, we do take the allegations very seriously as they relate to health and safety. We have immediately launched an internal investigation of the Danish factories in collaboration with impartial external experts."
LM Wind Power has strict rules for how styrene is used in production, she says. Employees attend a two-day external course before joining the company and the use of personal-protection equipment is rigorously enforced for all styrene-related manufacturing processes, she adds.