Key facts about the former Kodaikanal factory

Detailed background on the former factory’s closure

The mercury thermometer factory was set up in Kodaikanal in Tamil Nadu in 1983. In 1987, Pond’s India entered the Unilever fold through the larger corporate acquisition of Chesebrough-Pond's. Pond's India, and with it the thermometer factory, merged with Hindustan Unilever Limited (then Hindustan Lever Ltd) in 1998.

The Kodaikanal factory manufactured mercury thermometers, a business that was not considered core to Unilever's long-term portfolio. The company had been reviewing the factory's future and had decided in January 2001 to exit the thermometer business, before the subsequent events described below.

In March 2001, Greenpeace and others informed HUL that glass scrap containing residual mercury had been sold to a scrap dealer about three kilometres from the factory. This sale breached company procedures. HUL closed manufacturing operations at the factory, began a thorough investigation and notified the Tamil Nadu Pollution Control Board (TNPCB).

HUL also engaged URS Dames and Moore as independent international environmental consultants to make an environmental assessment and risk assessment of the site. Their studies found no adverse impact on the environment outside the factory premises or in the Kodaikanal environment and did not find sufficient evidence linking former employees’ health conditions to their work at the factory. Soil remediation was required in identified areas within the site.

Environmental impact assessment and remedial measures

After operations ceased, mercury-bearing material, including glass scrap, was removed and sent to an approved mercury recycler in the United States with the required permissions. Plant machinery and materials used to manufacture thermometers were later decontaminated and safely disposed of.

Remediation of contaminated soil was required only in identified areas within the former factory premises. The clean-up standard of 20 mg/kg of mercury in soil was based on a site-specific risk assessment undertaken by CSIR-NEERI, reviewed by IIT Delhi and expert scientific committees, and approved by the TNPCB and the Central Pollution Control Board (CPCB).

The 20 mg/kg standard was set at a safe level to protect human health and the environment. A lower threshold would have required more excavation and tree removal, increasing the risk of soil erosion and ecological damage in the hilly terrain. The remediation approach was validated through detailed studies, regulatory reviews and a successful trial before full-scale implementation. It was also examined through judicial and regulatory processes, with both the National Green Tribunal (NGT) and the Supreme Court ultimately allowing the remediation to proceed based on the approved standard and scientific evidence.

HUL completed the soil remediation in 2025 in accordance with directions and approvals from central and state authorities and under the supervision of leading scientific institutions. The completion of remediation marks the successful conclusion of efforts to address the contamination within the factory premises, with the objective of ensuring the long-term protection of both people and the surrounding ecosystem. HUL is now carrying out post-remediation work as per the direction of the statutory authorities.

Employee health

The Kodaikanal factory had stringent occupational health and safety systems in place before it closed in 2001. Internal monitoring and audits by statutory authorities during the factory’s operations did not identify adverse health effects attributable to employees’ work at the site. After the factory closed, several expert reviews examined the health of former employees. These included:

• A comprehensive medical examination conducted by a panel of doctors
• A study by the Certifying Surgeon from the Inspectorate of Factories
• A study by Dr P N Viswanathan of the Industrial Toxicology Research Centre (ITRC)
• A study by Dr Tom van Teuenbroek of TNO, directed by the Tamil Nadu Pollution Control Board (TNPCB)
• A study by the Industrial Toxicology Research Centre (ITRC) directed by the Supreme Court Monitoring Committee.
• HUL’s occupational health monitoring findings were also independently endorsed by the All India Institute of Medical Sciences (AIIMS) and the National Institute of Occupational Health (NIOH).

These findings were also confirmed by an expert committee convened by the Madras High Court, including representatives from ITRC, AIIMS and NIOH. Its report in 2007 concluded: "The committee failed to find sufficient evidence to link the current clinical condition of the factory workers to the mercury exposure in the factory in the past".

In March 2016, HUL signed a settlement with former workers on humanitarian grounds, which the Madras High Court took on record. HUL agreed to provide ex gratia payments to 591 former workers or association members and their families to support livelihood and skills-development programmes.

Kodaikanal mercury matter: Frequently asked questions

• What happened at HUL’s former Kodaikanal factory in 2001?

  In March 2001, Greenpeace and others brought to HUL's attention that glass scrap containing residual mercury had been sold to a local scrap dealer about three kilometres from the factory. HUL's investigation confirmed that the sale breached company procedures. The Company immediately closed manufacturing operations at the factory, informed the Tamil Nadu Pollution Control Board (TNPCB) and began a comprehensive investigation.

• What action did HUL take when the issue came to light?

  HUL initiated an investigation, appointed independent environmental consultants, recovered mercury-bearing material from the scrapyard and took measures to safely manage it.

  HUL appointed URS Dames & Moore to conduct independent environmental and risk assessments. It recovered mercury-bearing glass scrap from the scrapyard, built five silt traps to prevent soil from leaving the site, and traced and recovered scrap that may previously have left the factory. In 2003, after obtaining the required permissions, HUL sent 290 tonnes of mercury-bearing material to the United States for mercury recovery and subsequent recycling or disposal.

• Did HUL dump mercury-contaminated glass waste outside the factory?

  No. Glass scrap containing residual mercury was sold to a scrap dealer about three kilometres from the factory in breach of company procedures. The investigation identified 5.3 metric tonnes of mercury-tainted glass scrap, containing approximately 0.15% residual mercury, sold in breach of procedure. HUL recovered 7.4 tonnes of scrap and the soil beneath it from the scrapyard and returned the material to the factory premises for safe storage.

• Was there an adverse environmental impact outside the factory premises?

  Environmental and risk assessment studies found no adverse environmental impact outside the factory premises. They identified areas within the site that required soil remediation. The URS, ERM, and NEERI-CSIR assessments covered multiple locations outside the factory including Pambar Shola, Pambar River, Kumbakari Falls, Kodaikanal Lake and the scrapyard site, and found no significant mercury-related risks. The reported mercury levels were found to be within safe and internationally accepted ranges.

• Did former employees suffer from mercury-related ill health because of their work at the factory?

  Several expert reviews conducted after the factory closed did not find sufficient evidence linking former employees’ health conditions to their work at the factory. These included medical examinations, studies by the Industrial Toxicology Research Centre (ITRC) and a TNPCB-directed study by TNO. In addition, the findings from our own occupational health monitoring were independently endorsed by the All India Institute of Medical Sciences (AIIMS) and the National Institute of Occupational Health (NIOH). These findings were also confirmed by an expert committee convened by the Madras High Court

• Were reported deaths or congenital conditions among former workers’ families linked to mercury exposure?

  Expert medical reviews did not establish a causal link between factory exposure and the reported deaths or congenital conditions. The records presented did not identify mercury exposure as a cause of death. Several independent expert bodies reviewed the available medical evidence.

• Did the 2016 settlement amount to an admission that workers’ health had been affected?

  No. The 2016 settlement was reached on humanitarian grounds, and not on the basis of any evidence that former employees had mercury-related ill health as a result of their occupation at the factory. It followed the Madras High Court’s suggestion that the parties seek an amicable resolution and was intended to support the long-term wellbeing of former employees and their families.

• What support did HUL provide to former employees after the factory closed?

  Workers were offered alternative employment, received a severance package above statutory requirements, and later received support under the 2016 humanitarian settlement.

  Workers were offered alternative employment at another company unit. The severance package exceeded statutory requirements and was approximately equal to six months’ salary for each completed year of service. The 2016 humanitarian settlement also provided ex gratia support to 591 former workers or association members and their families for livelihood and skills-development programmes.

• Did HUL delay or avoid cleaning up the factory site?

  HUL began seeking permission to remediate the site in 2002. In 2003, it sent 290 tonnes of mercury-bearing material to the United States. In 2006, it completed the approved decontamination and disposal of plant and machinery.

  Pre-remediation work began in May 2009 and stopped in October 2010 after the clean-up standard was contested and the TNPCB required further studies by national institutions such as IIT Delhi, National Botanical Research Institute (NBRI) and Indian Institute for Soil and Water Conservation (IISWC). A remediation trial was completed in 2017, and full-scale remediation was approved in 2018. In 2018, the National Green Tribunal (NGT) accepted the remediation standard set by the authorities and directed to proceed with remediation. In 2019, the Supreme Court dismissed a further challenge and allowed soil remediation to proceed. The TNPCB subsequently issued the Consent-to-Establish in 2020 and Consent-to-Operate in 2021, enabling the remediation facilities to be established and operated under regulatory oversight. HUL completed soil remediation in 2025.

• What soil remediation standard was used, and who determined it?

  The Site-Specific Target Level was 20 mg/kg of mercury in soil. TNPCB set the standard following human-health and ecological risk assessments by CSIR-NEERI and IIT Delhi and consultations with the Scientific Experts Committee and the Central Pollution Control Board (CPCB).

  The human health risk assessment by CSIR-NEERI found that 25 mg/kg would protect future residential use, while IIT Delhi recommended 22.4 mg/kg based on ecological risk assessment. Applying a precautionary approach, and the recommendations of the Scientific Experts Committee and CPCB, TNPCB set the standard lower at 20 mg/kg. The National Green Tribunal reaffirmed the standard, based on the eight-member scientific committee consisting of IIT Madras, IIT Bombay, IIT Delhi (two members), CSIR-NEERI, ITRC, AIIMS and ICMR. In 2019, the Supreme Court dismissed a challenge and allowed soil remediation to proceed.

• Who carried out the soil remediation?

  HUL carried out the soil remediation with guidance from NEERI and IISWC, supported by specialist environmental consultants and remediation service providers.

  The National Environmental Engineering Research Institute (NEERI), Nagpur, and the Indian Institute of Soil and Water Conservation (IISWC), Ooty, provided guidance. Environmental Resources Management and specialist remediation providers also supported the work.

  The Scientific Experts Committee and TNPCB monitored the remediation, with the Local Area Environment Committee and Kodaikanal Municipality also associated with the process.

• Why was the standard 20 mg/kg rather than a lower figure used elsewhere?

  There is no single or universal mercury clean-up standard that applies across India and other countries. Some figures used internationally are screening criteria that indicate whether the site is contaminated or not, and further assessment may be needed – they are not the remediation standard. The remediation standard is set based on site-specific risk assessment. At HUL’s former factory site, the 20 mg/kg standard was based on a site-specific human-health and ecological risk assessment, and set by TNPCB, based on the recommendation of the Scientific Experts Committee and CPCB. Using a lower remediation standard could have required substantially more excavation, increasing soil erosion and ecological risks in the hilly terrain.

• What remediation process was used?

  The remediation process involved soil washing and vacuum retorting. Impacted soil was excavated, mixed with water, agitated, scrubbed, washed and separated into different size fractions. Mercury content in each fraction was analysed. Fractions above the remediation standard were heated in a vacuum retort, and the mercury was vapourised and condensed into elemental mercury. Treated soil that met the prescribed standard was backfilled at the excavated locations, and the area was rehabilitated.

• Who oversaw and validated the remediation?

  The remediation was carried out with guidance from the National Environmental Engineering Research Institute (NEERI) and IISWC and support from specialist environmental consultants and remediation service providers. CPCB, TNPCB, and the Scientific Experts Committee monitored the work. The Local Area Environment Committee and Kodaikanal Municipality were also associated with the process. CSIR-NEERI and IIT Madras independently validated remediation. Further sampling and validation were carried out by CPCB and TNPCB, and the site remediation was cleared.

• What safeguards were used during remediation?

  Soil remediation was carried out under strict health, safety and environmental controls, in accordance with approved operating procedures and regulatory requirements.

  All personnel involved in the remediation activities received specialised training and were supported by a comprehensive occupational health programme. This included medical examinations at the start, during and at the end of employment, regular monitoring of workplace mercury vapour levels, biological monitoring of mercury levels in urine, mandatory use of personal protective equipment (including mercury-vapour respirators), and stringent hygiene protocols. The site also had a full-time occupational health physician and a dedicated occupational health centre.

  Environmental safeguards were implemented throughout the remediation process. Mercury levels in air were continuously monitored at work areas and along the site boundary, including through continuous monitoring stations operating 24 hours a day. Soil, water and air were regularly monitored, process water was treated and reused, and all waste was managed and disposed of in accordance with approvals from the TNPCB.

  Additional measures were taken to prevent soil movement, dust generation and water runoff. These included controlled excavation, water sprinkling, boundary barriers, soil-retaining walls, silt-settling tanks and silt traps. Work was suspended during periods of rainfall, and remediated areas were stabilised using geo-jute blankets and vegetation cover. Tree removal was limited to what was necessary for access, excavation and worker safety, and was carried out only with the required regulatory approvals.

• How was hazardous waste and recovered mercury managed, and what is the current status?

  Hazardous waste generated during soil remediation was managed in accordance with regulatory requirements and under the oversight of the Tamil Nadu Pollution Control Board (TNPCB). The waste was collected, stored, pre-treated, transported and disposed of at authorised Treatment, Storage and Disposal Facilities (TSDFs) in line with the applicable Hazardous Waste Authorisation issued by the TNPCB. Recovered mercury has been safely collected and stored. Its dispatch to authorised re-users will be undertaken in accordance with directions issued by the Central Pollution Control Board (CPCB) and the TNPCB.

• Why were trees removed, and what compensatory measures were taken?

  Trees were removed only where necessary to have access, excavate impacted soil and protect worker safety, following the required approvals. The work formed part of the Soil Remediation Upscaling Plan approved by TNPCB and was carried out after permission from the Dindigul District Hill Area (Preservation of Trees) Committee. HUL has planted more than ten times the number of trees that were removed, at the remediated area, a nearby campus and at an area allotted by the District authorities.

• What is HUL's position on claims made in Heavy Metal: How a Global Corporation Poisoned Kodaikanal?

  The book ‘Heavy Metal’, on the Kodaikanal former thermometer factory, contains significant inaccuracies and omits key findings from reviews by independent experts, scientific institutions and regulatory authorities. HUL's position is based on an extensive body of scientific and regulatory evidence.

• Wasn’t it because of Sofia Ashraf’s 2015 “Kodaikanal Won’t” song that forced HUL to settle with the former employees?

  No. In 2001, the workers were offered alternative employment at another company unit. The severance package exceeded statutory requirements and was approximately equal to six months’ salary for each completed year of service. The 2016 settlement was reached on humanitarian grounds and was not due to former employees suffering from ill health as a result of their occupation at the factory. It followed the Madras High Court’s suggestion that the parties seek an amicable resolution and was intended to support the long-term wellbeing of former employees and their families.

Timeline of the Kodaikanal issue