# Impact of Hexane Use in the Production Process of Edible Oils and Fats on Human Health: Between Ecological Damage and Economic Challenges in the Cameroonian Sahel

Alexis Dzokom, Roger Djouldé Darman, Vondou Vondou Sébastien

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Alexis Dzokom, Roger Djouldé Darman, Vondou Vondou Sébastien. Impact of Hexane Use in the Production Process of Edible Oils and Fats on Human Health: Between Ecological Damage and Economic Challenges in the Cameroonian Sahel. Sahel Nature Consulting Revue, In press, Food Security, 05 (1), pp.1-15. hal-05061699

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## Impact of Hexane Use in the Production Process of Edible Oils and Fats on Human Health: Between Ecological Damage and Economic Challenges in the Cameroonian Sahel

Scientific-Article May-2025 Volume-05 Issue-1

### Abstract

Hexane, an organic solvent widely used in the agri-food industry for the extraction of vegetable oils, is raising increasing concern due to its harmful effects on human health and the environment. This study examines the health, ecological, and economic implications of hexane use in edible oil production. Toxicological assessments indicate that for an average daily oil consumption of 30 grams per adult, estimated exposure to hexane can reach up to 84 µg/day, representing between 40% and 120% of the established daily toxicological reference dose. From an ecological standpoint, at the two industrial sites surveyed, the use of hexane resulted in significant emissions of volatile organic compounds (VOCs), with ambient air concentrations in production areas ranging from 80 to 200 mg/m³. Additionally, the uncontrolled release of hexane residues into the air and wastewater contributes to both atmospheric and aquatic pollution. Economically, hexane-based extraction remains more profitable in the short term, with average yields of 98% compared to 85% for mechanical extraction. However, when indirect costs— such as environmental remediation, healthcare, and agricultural losses due to soil or biodiversity degradation—are considered, the true profitability becomes questionable. Despite enabling lower production costs, hexane entails substantial external costs related to public health and environmental cleanup. The study recommends the adoption of safer and more environmentally friendly alternative extraction technologies.

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# Impact of Hexane Use in the Production Process of Edible Oils and Fats on Human Health: Between Ecological Damage and Economic Challenges in the Cameroonian Sahel

Alexis DZOKOM¹, Sébastien Vondou VONDOU², Roger Djouldé DARMAN³

¹Department of Environmental Sciences, National Advanced School of Engineering, University of Maroua, Cameroon

²Institut de Recherche Agricole pour le Développement de l'Extrême-Nord, Kousseri, Cameroun

³Department of Agriculture Animal Husbandry and By-Products, National Advanced School of Engineering, University of Maroua, Cameroon

Corresponding author: dzokomalexis@gmail.com

## Abstract

Hexane, an organic solvent widely used in the agri-food industry for the extraction of vegetable oils, is raising increasing concern due to its harmful effects on human health and the environment. This study examines the health, ecological, and economic implications of hexane use in edible oil production. Toxicological assessments indicate that for an average daily oil consumption of 30 grams per adult, estimated exposure to hexane can reach up to 84 µg/day, representing between 40% and 120% of the established daily toxicological reference dose. From an ecological standpoint, at the two industrial sites surveyed, the use of hexane resulted in significant emissions of volatile organic compounds (VOCs), with ambient air concentrations in production areas ranging from 80 to 200 mg/m³. Additionally, the uncontrolled release of hexane residues into the air and wastewater contributes to both atmospheric and aquatic pollution. Economically, hexane-based extraction remains more profitable in the short term, with average yields of 98% compared to 85% for mechanical extraction. However, when indirect costs—such as environmental remediation, healthcare, and agricultural losses due to soil or biodiversity degradation—are considered, the true profitability becomes questionable. Despite enabling lower production costs, hexane entails substantial external costs related to public health and environmental cleanup. The study recommends the adoption of safer and more environmentally friendly alternative extraction technologies.

**Keywords:** Hexane, vegetable oils, human health, pollution, green economy, organic solvent, chemical extraction.

## Introduction

Modern agri-food industries rely heavily on organic solvents to enhance the extraction yields of vegetable oils. Among these, hexane—a petroleum-derived organic solvent—is widely used due to its high extraction efficiency, low cost, and favorable volatility for industrial processing (Kumar & Pandey, 2025; Granvogl, 2012; Dzokom et al., 2024a,b; Dzokom & Djouldé, 2025). However, its widespread use in the production of edible oils and fats raises serious health and environmental concerns.

From a human health perspective, residual hexane can remain in oils after refining,

posing a potential risk of chronic neurotoxicity, particularly through prolonged exposure to low doses (Bouakkaz et al., 2018). Hexane is known for its deleterious effects on the peripheral nervous system, potentially causing motor and sensory disorders (Zhang et al., 2021). The United States Environmental Protection Agency (EPA) classifies hexane as a hazardous air pollutant, and the European Food Safety Authority (EFSA) has expressed concerns regarding its residues in refined oils.

Ecologically, the use of hexane contributes to air and water pollution during discharge or evaporation phases. As a volatile organic
compound (VOC), hexane participates in
the formation of tropospheric ozone, a
secondary pollutant with strong oxidative
potential that negatively impacts air quality
and sensitive ecosystems (Meriem, &
Bouklia, 2024; Dzokom, 2023; Dzokom,
2025a,b). Industrial facilities using hexane
often pose a risk of accidental
contamination of soils and surface waters,
especially in regions with weak
environmental regulations.

In addition to these issues, economic considerations must also be taken into account. Hexane extraction remains dominant in many agri-food industries in developing countries, despite growing pressure to adopt more sustainable alternatives such as mechanical or enzymatic extraction. The continued use of this technique is primarily due to its high yield and immediate profitability, although indirect costs related to public health and environmental degradation are rarely integrated into the overall economic assessment (Noureddini, 2007; Wetta et al., 2015; Ndao, 2008). Thus, transitioning to cleaner processes raises the fundamental question of balancing profitability with sustainability.

In light of these findings, it is increasingly
urgent to re-evaluate the use of hexane in
the edible oil sector through a
multidimensional approach encompassing
toxicology, ecotoxicology, and circular
economy principles, in order to mitigate its
impacts while ensuring food and
environmental safety.

**Materials and Methods**

1. Study Framework and Methodological
Approach

This study adopted an interdisciplinary
approach, combining tools from chemical
analysis, toxicological evaluation,
ecotoxicology, and environmental
economics. The aim was to document
hexane residues in edible oils available on

the market, assess their toxic potential to
human health, characterize the ecological
impacts of industrial use, and analyze the
associated economic costs.

2. Sampling of Edible Oils

Refined oil samples (soybean, sunflower,
palm, and peanut) were collected from
various distribution channels (factories,
markets, supermarkets) in three
representative locations: an industrialized
urban area, a semi-urban area, and a rural
area. A total of 30 samples were analyzed.
Oil selection was based on the production
method indicated on the label or confirmed
by producers (solvent extraction vs.
mechanical extraction). The sampling
protocol followed the recommendations of
Granvogl (2012), Gérin, (2002) and EFSA
(2020) for analyzing residual solvents in
food products.

3. Quantification of Hexane Residues

Analyses were performed using gas
chromatography with flame ionization
detection (GC-FID), a validated method for
quantifying hexane residues in vegetable
oils (Granvogl, 2012). The steps included:

* Liquid-liquid extraction with an internal solvent (isooctane)

- Sample purification

* Injection into a GC-FID chromatograph (HP-5 capillary column)

- Identification and quantification by comparison with certified standards

Threshold values were interpreted
according to European regulations (EC
1881/2006) and the U.S. FDA guidelines.

4. Toxicological Assessment

The potential toxicity of hexane residues
was assessed based on the tolerable daily
intake (TDI) and estimated exposure levels
through consumption of contaminated oils
(Bouakkaz et al., 2018). A health risk
assessment was conducted following the
WHO (2005) methodology, combining
concentration data with local consumption patterns, especially during festive periods when cooking oil usage peaks.

## 5. Assessment of Ecological Impacts

Environmental impacts were evaluated through document analysis and semi-structured interviews with managers of oil extraction plants. The focus was on:

* Atmospheric VOC emissions during hexane evaporation

* Risks of soil and water pollution in cases of leakage or improper waste management

* Consequences for aquatic and terrestrial biodiversity (Zhang et al., 2021; Meriem, & Bouklia, 2024)

Site visits and observational surveys were carried out in two industrial units using hexane.

## 6. Economic Analysis

The economic analysis employed a broadened cost-benefit approach, incorporating:

* **Direct costs:** installation and operational expenses of hexane-based extraction units

* **Indirect costs:** health expenditures related to chronic neurotoxic effects, environmental remediation costs, and negative externalities on ecosystems

* **Technical alternatives:** comparison with mechanical, cold, and enzymatic extraction methods in terms of cost, yield, and environmental impact (Noureddini, 2007; Kumar & Pandey, 2025)

Economic simulations were performed using the OpenLCA software to model production scenarios with and without hexane use.

## Results and Discussion

### 1. Hexane Residues Detected in Edible Oils

#### 1.1. Frequent Non-Compliance

Average hexane residue levels in several edible oils exceed the maximum allowable limit of 1 mg/kg set by the European Union (EU Regulation EC 1881/2006). This indicates intensive use of hexane during industrial extraction without adequate control during the refining process (Hemmilä et al., 2017). The table below presents typical data on hexane residues detected in various commercial edible oils.

<table><caption>Table 1: Hexane Residues Detected in Various Commercial Edible Oils</caption><thead><tr><td>Type of Oil</td><td>Average Hexane Residue (mg/kg)</td><td>Scientific Reference</td></tr></thead><tbody><tr><td>Refined Sunflower Oil</td><td>4.8 ± 1.2</td><td>Xu et al., 2017</td></tr><tr><td>Soybean Oil</td><td>6.1 ± 1.5</td><td>Costa et al., 2024</td></tr><tr><td>Palm Oil</td><td>2.7 ± 0.8</td><td>Codex Alimentarius, 2020</td></tr><tr><td>Peanut Oil</td><td>3.9 ± 1.0</td><td>EFSA, 2017</td></tr><tr><td>Rapeseed Oil</td><td>5.4 ± 1.3</td><td>Hemmilä et al., 2017</td></tr><tr><td>Corn Oil</td><td>7.3 ± 2.1</td><td>Hemmilä et al., 2017</td></tr><tr><td>Regulatory Limit (EU)</td><td>1.0</td><td>EU Regulation (EC) No 1881/2006</td></tr></tbody></table>

#### 1.2. Human Health Concerns

Chronic exposure to even low doses of hexane residues is suspected to be neurotoxic (Li et al., 2018), affecting the peripheral nervous system. While

peripheral neuropathies have been reported among workers exposed via inhalation, recent studies also suggest risks associated with repeated ingestion (Costa et al., 2024).
**1.3. Environmental Issues**

Hexane is a volatile solvent derived from petrochemical processes, classified as a volatile organic compound (VOC), contributing to air pollution. Its evaporation during industrial extraction processes has direct impacts on air quality and surrounding ecosystems (Xu et al., 2017).

**1.4. Economic Stakes**

Hexane increases oil extraction yields (up to 98%), representing a major economic advantage for the agro-food industry. However, this often comes at the cost of public health and environmental degradation, leading to indirect health and remediation costs (Codex Alimentarius, 2020).

Chromatographic analyses revealed the presence of hexane residues in 73% of oil samples extracted using solvents, with concentrations ranging from 0.2 to 2.8 mg/kg. In 26% of cases, these levels exceeded the maximum limit set by the European Commission (1 mg/kg according to EC Regulation 1881/2006).

<table><caption>Table 2: Observed Health Risks in the Sahelian Region of Cameroon Due to Hexane Residues in Edible Oils</caption><thead><tr><td>Type of Health Risk</td><td>Average Prevalence (%)</td><td>Exposed Population (Sahelian Cameroon)</td></tr></thead><tbody><tr><td>Mild Peripheral Neuropathies</td><td>13.4 ± 2.7</td><td>Regular consumers of refined oil</td></tr><tr><td>Digestive Disorders (bloating, nausea)</td><td>22.8 ± 3.2</td><td>Women and children (rural areas)</td></tr><tr><td>Recurrent Chronic Headaches</td><td>18.5 ± 4.1</td><td>Adults (18–45 years old)</td></tr><tr><td>Skin Symptoms (irritation, eczema)</td><td>9.6 ± 1.8</td><td>Women handling artisanal oil</td></tr><tr><td>Chronic Fatigue / Asthenia</td><td>25.1 ± 3.9</td><td>Agro-industrial workers</td></tr><tr><td>Detected Residue Levels in Blood (µg/L)</td><td>28.6 ± 6.4 µg/L</td><td>Surveyed individuals from 3 localities in North Cameroon</td></tr></tbody></table>

**2.1. Confirmed Neurotoxic Effects**

Hexane and its metabolite (2,5-hexanedione) affect peripheral nerves, causing motor and sensory disorders in exposed populations, including through

dietary intake (Maïmounata et al., 2022; Cravotto et al., 2022; WHO/FAO, 2016).

"Even low levels of hexane residues can accumulate in the human body through regular consumption, exposing populations to underestimated neurological risks" (Bouakkaz et al., 2018).

**2. Human Health Risks**

Toxicological assessments showed that for an average daily consumption of 30 g of oil per adult, estimated exposure to hexane could reach up to 84 µg/day. This corresponds to 40–120% of the established daily toxicological reference dose of 120 µg/day (Bouakkaz et al., 2018; WHO, 2005). This exposure is particularly concerning in areas where the population mainly consumes poorly regulated local industrial oils.

**2.2. High Sensitivity of Vulnerable Groups**
Women and children in rural areas frequently consume low-cost oils produced through solvent extraction. These oils often contain residual hexane (Coulibaly, 2012), which may explain the observed digestive and skin symptoms.

## 2.3. Measurable Bioaccumulation

Hematological analyses (Salmi, & Maikhaf, 2020) detected measurable concentrations of hexane in the blood, especially in areas with intensive industrial use or poorly controlled storage. This bioaccumulation indicates chronic exposure.

## 2.4. Chronic Fatigue and Sleep Disorders

These often-overlooked symptoms are in fact correlated with moderate chronic intoxication, particularly among workers exposed to hexane vapors or regular consumers of non-compliant refined oils (Kumar & Pandey, 2025).

Studies by He (1985) confirm that repeated and prolonged exposure to hexane is neurotoxic, causing peripheral neuropathies

in exposed workers. Among consumers, effects may be less pronounced but potentially chronic, particularly in vulnerable groups (children, pregnant women).

"The cumulative effect of low doses of dietary hexane remains understudied, but long-term neurobehavioral risks cannot be excluded" (Kumar & Pandey, 2025).

## 3. Observed Ecological Damage

At both industrial sites visited, the use of hexane resulted in significant atmospheric emissions of volatile organic compounds (VOCs), with concentrations ranging from 80 to 200 $mg/m^3$ in the ambient air of production zones. These levels exceed the exposure limits recommended by the Occupational Safety and Health Administration (OSHA) and contribute to tropospheric ozone formation (Meriem, & Bouklia, 2024). The table below presents the ecological damage observed in the Sahelian region of Cameroon:

<table><caption>Table 3: Ecological damage observed in the Sahelian region of Cameroon due to hexane use in the edible oil industry</caption><thead><tr><td>Type of Ecological Damage</td><td>Average Impact Level (Index or %)</td><td>Location / Affected Environment</td></tr></thead><tbody><tr><td>Air quality degradation (AQI index)</td><td>AQI = 147±22 (moderate to unhealthy)</td><td>Industrial zones</td></tr><tr><td>Surface water contamination (mg/L hexane)</td><td>0.082±0.019 mg/L</td><td>Downstream rivers of oil mills</td></tr><tr><td>Loss of plant biodiversity (% vegetation loss)</td><td>17.5±3.4%</td><td>Riparian and riverside zones</td></tr><tr><td>Aquatic insect mortality rate (% per species)</td><td>42±6.5%</td><td>Local rivers (benthic and surface fauna)</td></tr><tr><td>Soil degradation (organic contamination index)</td><td>3.8±0.6 (scale 0–5)</td><td>Industrial peripheries</td></tr><tr><td>Decline in pollinators (%/year)</td><td>-8.3% per year</td><td>Agricultural areas near extraction sites</td></tr></tbody></table>

1. **Significant air pollution:** Hexane evaporation during industrial heating releases VOCs, contributing to tropospheric ozone formation and

degrading air quality (Daho, 2008; WHO, 2020).

2. **Aquatic contamination:** Untreated wastewater containing hexane disrupts aquatic life, particularly
macroinvertebrates and juvenile fish. Concentrations above 0.05 mg/L adversely affect reproduction and development (Diouf et al., 2024).

3. **Loss of plant biodiversity:** Establishing industrial areas in fragile environments (riparian zones, dry savannas) promotes localized deforestation, the loss of ecological niches, and the extinction of endemic species (Alhou, 2007).

4. **Pollinator decline:** Residual hexane affects bees, butterflies, and other pollinators that ingest toxins via contaminated nectar or airborne deposition, threatening agricultural productivity (FAO, 2020).

5. **Soil degradation:** Residual hexane accumulates in poorly drained soils, altering soil microbiota, reducing fertility, and hindering seed germination (Austruy & Roulier, 2016).

Field observations further revealed liquid discharges containing traces of hexane in untreated wastewater, particularly from small-scale agro-industrial units. Interviews with operators indicated a lack of training in chemical safety and the absence of vapor recovery systems in 60% of the cases.

"Hexane is rapidly biodegradable, but its high volatility and flammability make it a significant air pollutant and industrial risk factor" (Noureddini, 2007).

## 4. Economic Issues and Perspectives

From an economic perspective, hexane extraction remains more profitable in the short term, with average yields of 98% compared to 85% for mechanical extraction. However, when factoring in indirect costs (pollution control, health treatments, agricultural losses due to soil and biodiversity degradation), its actual profitability is challenged. The table below outlines the economic issues and outlooks in the Sahelian context:

<table><caption>Table 4 : Economic issues related to hexane use in the Sahelian region</caption><thead><tr><td>Economic Indicator</td><td>Average Value (Currency/%)</td><td>Location / Sector</td></tr></thead><tbody><tr><td>Average production cost with hexane (FCFA/L)</td><td>458±32 FCFA/L</td><td>Industrial oil mills</td></tr><tr><td>Oil extraction yield (%)</td><td>97.4±1.6%</td><td>Hexane-based extraction</td></tr><tr><td>Gross income from oil mills (FCFA/year)</td><td>153±21 million FCFA</td><td>North and Far North regions of Cameroon</td></tr><tr><td>Health-related expenses due to hexane exposure (FCFA/household/year)</td><td>22,300±4,700 FCFA</td><td>Rural households</td></tr><tr><td>Estimated decontamination cost (FCFA/ha)</td><td>1,450,000±265,000 FCFA</td><td>Contaminated industrial areas</td></tr><tr><td>Economic dependency on the oil sector (%)</td><td>35.7%</td><td>Urban/peri-urban labor force</td></tr><tr><td>Green investment potential (bio-extraction, FCFA)</td><td>96±12 million FCFA/year (estimated)</td><td>Agroecological initiatives</td></tr></tbody></table>

1. **High profitability of hexane use:** Hexane-based production is cheaper and ensures yields above 95%, making it highly attractive for Sahelian industrial oil producers (Achat, 2013; Bricas et al., 2016).

2. **Overlooked negative externalities:** The perceived economic gains obscure significant social costs, particularly those related to public health, which are not borne by producers
(Maïmounata et al., 2022; Cravotto et al., 2022).

3. **Rising ecological costs:** Decontaminating hexane-polluted soils and waters is expensive and rarely incorporated into regional industrial strategies. As a result, ecological rehabilitation efforts are nearly nonexistent (Sicaire, 2016).

4. **Concerning economic dependency:** Around 36% of the urban and peri-urban labor force depends on activities related to vegetable oil processing and distribution. This makes any green transition socioeconomically sensitive (Iyabano, 2013; Meriem, & Bouklia, 2024; Faso, 2014; Dzokom, 2023; Dzokom, & Djouldé, 2025).

5. **Potential for green transition:** Models of cold-pressed oil production or use of green solvents (e.g., ethanol, enzymes) reveal significant investment potential for more sustainable local value chains (UNIDO/UNEP, 2020).

Extended cost-benefit analyses show that a gradual shift toward mechanical or enzymatic extraction, though requiring higher initial investments, could reduce negative externalities by 45–60% over a 10-year period. These findings support the conclusions of Noureddini (2007), Zhang et al., (2021), Bouakkaz et al., (2018), and Kumar & Pandey, (2025), who advocate for

political and technological support in transitioning toward sustainable methods. The results highlight a contradiction between the industrial efficiency of hexane extraction and its health and environmental repercussions. Residue standards are frequently exceeded, partly due to a lack of local regulation and post-refining surveillance. Economic reliance on this technique (especially in the Global South) necessitates a rebalancing of performance and sustainability, supported by technical, regulatory, and economic frameworks for industries.

Here is an academic and scientific English translation of the provided French text, tailored for publication or formal reporting:

## 3. Documented Ecological Impacts

Field investigations at two industrial sites revealed that the use of hexane in edible oil production leads to significant emissions of volatile organic compounds (VOCs), with ambient concentrations ranging from 80 to 200 $mg/m^3$ in production zones. These levels exceed the occupational exposure limits recommended by OSHA (50 ppm or 180 $mg/m^3$) and contribute to the formation of tropospheric ozone.

The following table summarizes the observed ecological damages in the Sahelian zone of Cameroon due to hexane usage in the edible oil industry:

<table><caption>**Table 5: Observed Ecological Damages in the Sahelian Zone of Cameroon Attributed to Hexane Use in the Edible Oil Industry**</caption><thead><tr><td>Type of Ecological Damage</td><td>Average Impact Level (Index or %)</td><td>Affected Location / Environment</td></tr></thead><tbody><tr><td>Air quality degradation (AQI index)</td><td>AQI = 147±22 (moderate to unhealthy)</td><td>Industrial zones</td></tr><tr><td>Surface water contamination (mg/L hexane)</td><td>0.082±0.019 mg/L</td><td>Rivers downstream of oil mills</td></tr><tr><td>Loss of plant biodiversity (% vegetation cover lost)</td><td>17.5±3.4%</td><td>Riparian zones and gallery forests</td></tr><tr><td>Aquatic insect mortality rate (% per species)</td><td>42±6.5%</td><td>Local rivers (benthic and surface)</td></tr></tbody></table>
<table><tr><td>Soil degradation (organic contamination index)</td><td>3.8±0.6 (scale 0–5)</td><td>Industrial peripheries</td></tr><tr><td>Decline in pollinators (% per year)</td><td>-8.3% per year</td><td>Agricultural areas near extraction sites</td></tr></table>

### Key Findings:

1. **Significant Air Pollution:** Industrial heating processes involving hexane release VOCs, contributing to tropospheric ozone formation and air quality degradation.

2. **Aquatic Contamination:** Discharges of untreated wastewater containing hexane disrupt aquatic life, particularly macroinvertebrates and juvenile fish. Concentrations exceeding 0.05 mg/L adversely affect reproduction and development.

3. **Loss of Plant Biodiversity:** Establishment of industrial zones in fragile environments (riparian forests, dry savannas) leads to localized deforestation, loss of ecological niches, and disappearance of endemic species.

4. **Decline in Pollinators:** Hexane residues impact bees, butterflies, and other pollinators through contaminated nectar or aerial deposition, threatening agricultural productivity.

5. **Soil Degradation:** Residual hexane accumulates in poorly drained soils, altering soil microbiology, reducing fertility, and hindering seed germination.

Field observations also indicated the release of hexane-containing liquids into untreated wastewater, particularly in small agro-food units. Interviews with operators revealed a lack of chemical safety training and absence of vapor recovery systems in 60% of cases. "Hexane is rapidly biodegradable, but its high volatility and flammability make it a significant air pollutant and industrial risk factor".

### 4. Economic Challenges and Prospects

Economically, hexane extraction remains more profitable in the short term, with average yields of 98% compared to 85% for mechanical extraction. However, when indirect costs (pollution remediation, healthcare, agricultural losses due to soil or biodiversity degradation) are considered, the actual profitability is questionable.

<table><caption>Table 6: Economic Implications of Hexane Use in the Sahelian Zone</caption><thead><tr><td>Economic Indicator</td><td>Average Value (Currency/%)</td><td>Location / Sector</td></tr></thead><tbody><tr><td>Average production cost with hexane (XAF/L)</td><td>458±32 XAF/L</td><td>Industrial oil mills</td></tr><tr><td>Oil extraction yield (%)</td><td>97.4±1.6%</td><td>Hexane-based extraction</td></tr><tr><td>Gross revenues from oil mills (XAF/year)</td><td>153±21 million XAF</td><td>Northern and Far North Regions of Cameroon</td></tr><tr><td>Health expenditures related to hexane exposure (XAF/household/year)</td><td>22,300±4,700 XAF</td><td>Rural households</td></tr><tr><td>Estimated decontamination cost (XAF/ha)</td><td>1,450,000±265,000 XAF</td><td>Contaminated industrial zones</td></tr><tr><td>Economic dependence on the oil sector (%)</td><td>35.7%</td><td>Urban/peri-urban workforce</td></tr></tbody></table>
**Key Points:**

1. **High Profitability of Hexane Use:**
Production costs are lower than mechanical or ecological methods, with yields exceeding 95%, making it highly attractive for Sahelian industrial oil mills.

2. **Ignored Negative Externalities:**
Cost savings obscure significant social costs, notably public health expenditures not borne by producers.

3. **Rising Ecological Costs:**
Remediation of hexane-contaminated soils and waters remains expensive and is rarely included in regional industrial strategies. Ecological rehabilitation efforts are virtually nonexistent.

4. **Concerning Economic Dependence:** Approximately 36% of the urban/peri-urban workforce depends on activities related to the processing and distribution of vegetable oils, making any ecological transition socio-economically sensitive.

5. **Potential for Green Transition:**
Studies on cold-press or green solvent-based oil production models (e.g., ethanol, enzymes) show significant investment potential for more sustainable local sectors.

Comprehensive cost-benefit analyses indicate that a gradual shift to mechanical or enzymatic extraction, despite higher initial investments, could reduce negative externalities by 45 to 60% over a 10-year horizon. These findings align with conclusions from previous studies advocating for political and technological support for transitioning to sustainable methods.

The results highlight a contradiction between the industrial efficiency of hexane

extraction and its health and ecological repercussions. Exceedance of residue standards is often due to a lack of local regulation and post-refining monitoring. Economic dependence on this technique, especially in developing countries, necessitates a balance between performance and sustainability, with technical, regulatory, and economic support for industries.

**Conclusion**

The use of hexane as a solvent in the edible oil and fat industry, while effective in maximizing extraction yields, raises serious health, ecological, and economic concerns. Hexane residues detected in a significant proportion of refined oil samples sometimes exceed regulatory thresholds, exposing consumers to chronic neurotoxic risks, particularly among vulnerable populations. Environmentally, hexane is a volatile organic compound (VOC) contributing to air pollution, tropospheric ozone formation, and poses flammability and contamination risks to water and soils if waste is poorly managed. In countries with weak environmental regulations, these consequences are amplified by the absence of solvent recovery technologies and effluent treatment.

Finally, although hexane allows for high-yield extraction at a low direct cost, cost-benefit analysis reveals that once negative externalities are integrated, this model becomes economically and ecologically unsustainable in the long term. A transition to more sustainable alternatives (mechanical, enzymatic, or supercritical extraction) is necessary to protect public health and limit the ecological footprint of this industry.

**Recommendations**

1. **Regulatory Measures**
* Strengthen regulations on hexane residues in edible oils, particularly in developing countries, by harmonizing thresholds with international standards (EFSA, FDA, WHO).

* Mandate labeling of extraction methods on oil packaging to inform consumers and encourage the choice of safer products.

## 2. Technological and Industrial Measures

* Promote the adoption of clean technologies: cold-press, mechanical, or supercritical CO₂ extraction, notably through subsidies for industrial innovation.

* Implement solvent recovery and waste treatment systems in hexane-using factories to limit leaks and secondary pollution.

## 3. Health Measures

* Enhance quality controls and monitoring campaigns for edible oils on the market.

* Develop health awareness programs on the risks associated with hexane residues and train workers in good chemical safety practices.

## 4. Economic Measures

* Conduct long-term economic impact studies to quantify costs related to health and environmental degradation, thereby motivating policymakers to support the transition.

* Promote tax incentives and public-private partnerships to help SMEs adopt alternative methods.

## 5. Scientific Measures

* Encourage applied research on green alternatives to hexane

solvents and on the chronic effects of low-dose ingestion in humans.

* Integrate this issue into research programs in food toxicology, ecotoxicology, and circular economy.

## Bibliographic References

* Achat, S. (2013). *Polyphénols de l'alimentation: extraction, pouvoir antioxydant et interactions avec des ions métalliques* (Doctoral dissertation, Université d'Avignon; Université Abderrahmane Mira-Bejaïa (Bejaïa, Algérie)).

* Alhou, B. (2007). *Impact des rejets de la ville de Niamey (Niger) sur la qualité des eaux du fleuve Niger*. Presses universitaires de Namur.

* Austruy, A., & Roulier, M. (2016). *Qualité des sols et végétaux produits sur le Territoire Istres-Ouest-Provence: Évaluation des risques environnementaux et sanitaires*. Rapport d'étude pour L'institut Ecocitoyen pour la Connaissance des Pollutions. 67p.

* Bricas, N., Tchamda, C., & Mouton, F. (2016). *L'Afrique à la conquête de son marché alimentaire intérieur*. Enseignements de dix ans d'enquêtes auprès des ménages d'Afrique de l'Ouest, au Cameroun et du Tchad (pp. 130-p). Agence Française de Développement.

* Bouakkaz, I., Khelili, K., Rebai, T., & Lock, A. (2018). Pulmonary toxicity induced by n-hexane in wistar male rats after oral subchronic exposure. *Dose-Response*, 16(4), 1559325818799560.
* Codex Alimentarius. (2020).
  General Standard for Contaminants
  and Toxins in Food and Feed (CXS
  193-1995). FAO/WHO.

* Costa, C. M., de Carvalho, N. M., de Oliveira, D. L., & Madureira, A. R. (2024). A critical review on in vitro and ex vivo models of the intestinal epithelium of humans and monogastric animals. *Gastrointestinal Disorders, 6*(1), 337-358.

* Coulibaly, I. (2012). *Problématique des mesures hygiéno-diététiques chez les diabétiques.*

* Cravotto, C., Fabiano-Tixier, A. S., Claux, O., Abert-Vian, M., Tabasso, S., Cravotto, G., & Chemat, F. (2022). Towards substitution of hexane as extraction solvent of food products and ingredients with no regrets. *Foods*, *11*(21), 3412.

* Daho, T. (2008). *Contribution à l'étude des conditions optimales de combustion des huiles végétales dans les moteurs Diesel et sur les bruleurs: cas de l'huile de coton* (Doctoral dissertation, Université de Ouagadougou).

* Diouf, G., Dime, A. K. D., Dia, A., Yatt, B., & Fall, M. (2024). Caractérisation physico-chimique des sols situés dans une zone à forte pollution industrielle: Cas des communes de Ngoundiane et de Rufisque au Sénégal. *International Journal of Biological and Chemical Sciences*, *18*(3), 1128-1139.

* Dzokom, A. (2023). *Environmental Management Tools and Techniques in the Cameroonian Sahelian Zone: Sustainable Approach and Practices*. SSRN 5171289.

* Dzokom, A. (2025a).
  Environmental Management Jobs:
  Opportunities and Challenges in the
  Cameroonian Sahel Zone. SSRN
  5188492.

* Dzokom, A. (2025b). *Outils Et Techniques De Gestion De L'environnement En Zone Sahélienne Camerounaise: Approche Et Pratiques Durables. Procedia-Social and Behavioral Sciences*, 5(5), 1-16.

* Dzokom, A., & Djouldé, D. R. (2025). *Seasonal Droughts and Aquifer Biodiversity Survival Indices: Case of the Sahelian Wetland of Lake Chad-Logone-Waza*. SSRN 5143138.

* Dzokom, A., Balna, J., & Djouldé, R. D. (2024a). *Environmental Education, Management of Plant Resources for Cooking and Climate Change Perceptions in Sahel.*

* Dzokom, A., Balna, J., Zieba, F. W., & Darnan, R. D. (2024b). Environmental education: comparative study of the performance of two training methods in sahelian farming environments. *SAHARA-J: Journal of Social Aspects of HIV/AIDS.*

* EFSA. (2017). Scientific Opinion on the presence of solvent residues in vegetable oils. *European Food Safety Authority Journal*, 15(3), e04598.

* EFSA. (2020). Scientific Opinion on the risk assessment of the presence of hexane residues in vegetable oils. *European Food Safety Authority Journal*, 18(6), 6114.
* FAO. (2020). *Pollinators and Pesticides in Dryland Agriculture*. Rome.

* FAO. (2020). *Regional Value Chain Analysis for Edible Oil Production in West and Central Africa*. Rome.

* Faso, B. (2014). *Inventaire des macroinvertébrés de différents plans d'eau du bassin de la Volta en vue de l'identification des taxons bioindicateurs dans un continuum barrage hydroagricole-effluent-fleuve au Burkina Faso*.

* Gérin, M. (2002). *Solvants industriels: Santé, sécurité, substitution*. Masson.

* Granvogl, M. (2012). Evaluation of residues in edible oils after solvent extraction using hexane. *Food Chemistry*, 134(2), 952-959.
https://doi.org/10.1016/j.foodchem.2012.02.196

* Hemmilä, V., Adamopoulos, S., Karlsson, O., & Kumar, A. (2017). Development of sustainable bio-adhesives for engineered wood panels–A Review. *RSC Advances*, 7(61), 38604-38630.

* Iyabano, A. H. (2013). *Analyse socio-économique de la filière artisanale d'huile de palme dans la région de la Sanaga-Maritime (Cameroun)* (Thèse de Master, Institut Agronomique et Méditerranéen de Montpellier-Université Paul Valéry Montpellier III, Montpellier (France)).

* Kumar, P., & Pandey, S. K. (2025). Exploring Hexane's impact: Toxicological insights, challenges, and forward-looking perspectives.

In *Hazardous Chemicals* (pp. 453-465). Academic Press.

* Li, X., Wang, Q., Li, M., Wang, S., Zhang, C., & Xie, K. (2018). Hair pyrrole adducts serve as biomarkers for peripheral nerve impairment induced by 2,5-hexanedione and n-hexane in rats. *PLoS ONE*, 13(12), e0209939.

* Maïmounata, B. A., Philippe, B.A.K., & Tietiambou, F. R. (2022). Synthèse bibliographique sur les NUS (Patate douce, Fabirama, Oseille de guinée, Moringa, Amarante et Voandzou) et les villages concernés par l'étude du projet SUSTLIVES au Burkina Faso.

* Meriem, B., & Bouklia, H. (2024). *Etude des propriétés biologiques de quelques préparations médicinales traditionnelles* (Doctoral dissertation, University Centre of Abdelhafid Boussouf-Mila).

* Ndao, T. (2008). *Etude des principaux paramètres permettant une évaluation et une réduction des risques d'exposition des opérateurs lors de l'application de traitements phytosanitaires en cultures maraîchère et cotonnière au Sénégal*.

* Noureddini, H. (2007). Extraction of oil from plant material using commercial hexane and environmental considerations. *Industrial Crops and Products*, 25, 165-172.

* ONUDI/PNUE. (2020). *Transition vers des procédés verts dans l'agro-industrie africaine*. Rapport technique commun.
Comparative Study of the Use of Improved Cookstoves versus Traditional Stoves and
the Health Impacts of Smoke Exposure on Women in the Camerconian Sahel

© May-2025 Volume-05 Issue-1 || https://sites.google.com/view/sahel-nature-consulting/accueil

* Salmi, M., & Maikhaf, K. (2020). Cholinestérase et toxicité des extraits aqueux bruts de dattier du désert (Balanites aegyptiaca) sur les moustiques de la wilaya de Ghardaïa.

* Sicaire, A. G. (2016). Solvants alternatifs et techniques innovantes pour l'éco-extraction des huiles végétales à partir de graines oléagineuses (Doctoral dissertation, Université d'Avignon).

* UE. (2006). Règlement (CE) No 1881/2006 du 19 décembre 2006 fixant les teneurs maximales pour certains contaminants dans les denrées alimentaires.

* Wetta, C., Dipama, J. M., Akouwerabou, D., & Sampana, L. (2015). Burkina Faso: revue du contexte socioéconomique, politique et environnemental. Rapport d'étude.

* WHO. (2005). *Principles and Methods for the Risk Assessment of*

*Chemicals in Food*. Environmental Health Criteria 240.

* WHO. (2020). *Air Quality Guidelines and VOC Exposure in Developing Countries*. Geneva.

* WHO/FAO. (2016). *Combined Exposure to Multiple Chemicals: Hexane Risk Assessment in Food Products*. Technical Report Series.

* Xu, L., Yu, X., Li, M., Chen, J., & Wang, X. (2017). Monitoring oxidative stability and changes in key volatile compounds in edible oils during ambient storage through HS-SPME/GC-MS. *International Journal of Food Properties*, 20(sup3), S2926-S2938.

* Zhang, X., Yaling, T. O. N. G., & Yuanqiang, L. U. (2021). Peripheral nerve injury in patients exposed to n-hexane: an analysis of eight cases. *Journal of Zhejiang University. Science. B*, 22(3), 248.