Agent Name
CAS Number
Major Category
Biological Agents
Plant & Animal Dusts/Aerosols
Acute lung function changes associated with endotoxin levels have been measured in occupational environments: pig farming, animal feed, grain processing, waste and compost industry, and agricultural seeds (grass, cereal, or vegetable). [PMID 16361407] Levels in wastewater treatment plants are generally low, but higher levels may occur in indoor worksites like sludge dewatering areas. [PMID 15940720]
The source of endotoxins are the lipopolysaccharides (LPS) in the cell walls of Gram-negative bacteria. Endotoxins are the agents that cause mill fever and organic dust toxic syndrome. Significant concentrations of endotoxins are present in facilities of various industries: cotton and flax mills, grain silos, pulp and paper mills, sewage treatment plants, and animal confinement buildings. Other workers exposed to endotoxins include those processing compost, machining metal, and inhaling mists from contaminated humidifiers. After a heavy exposure, workers may develop fever and reduced pulmonary functional capacity. Repeatedly exposed workers develop tolerance showing a febrile response only after being away from the workplace for a weekend or longer (Monday morning fever). The causal role of endotoxin in byssinosis continues to be studied and debated. [Wald, p. 655-60] Low-dose endotoxin exposure may be beneficial to children, reducing the incidence of asthma. [Thorax 2002;57:86-90] Typical endotoxin levels in EU/m3 are 152 -13080 in poultry houses, 0.4 -101 in greenhouses, and 8-63 in mattress dust. Higher occupational endotoxin levels are associated with increased chronic bronchitis and non-atopic asthma and decreased allergic rhinitis and atopic asthma. [Reference #2] Swine confinement workers exposed to high levels of endotoxin should be provided with powered air-purifying respirators. "Exposure at the maximum value of 57,800 EU/m3 while wearing a properly fitting N95 respirator would be expected to limit respiratory exposures to about 3000 EU/m3, still 60-fold higher than the NOEL." [PMID 19177273] "Occupational endotoxin exposure has a protective effect on allergic sensitisation and hay fever but increases the risk for organic dust toxic syndrome and chronic bronchitis. Endotoxin's protective effects are most clearly observed among agricultural workers." [PMID 22039097] "Modern California dairy endotoxin exposures and shift length were associated with a mild acute decrease in forced vital capacity." [PMID 25563544] "Analysis by work environment group showed a decrease in lung cancer risk among workers highly exposed to endotoxins in dairy, cattle, poultry, pig farms and in waste collection and treatment, with strong statistically significant ORs between 0.25 (dairy farmers) and 0.51." [PMID 28490662]
Biomedical References

Exposure Assessment

Explanatory Notes
Relatively low endotoxin levels of 50-500 EU/m3 over 8 hours may cause across-shift decline in lung function. An exposure limit of 50 EU/m3 has been recommended. [PMID 16361407] See 2024 "Notice of Intended Changes" for TLV; [ACGIH TLVs and BEIs]

Adverse Effects

Chronic Bronchitis

Diseases, Processes, and Activities Linked to This Agent