NMP Exposure Summary 

The primary use of N-Methyl-2-Pyrrolidone (NMP) is as a solvent for a variety of 

industrial purposes. Occupational exposure can be divided into three major categories: (1) open 

system vapor/aerosol exposures; (2) open system vapor exposures; and (3) closed system vapor 

exposures. A number of studies have reported workplace exposure levels as high as 280 mg/m3

for both paint-strippers and in the microelectronics industry, but the majority of the values are 

much lower.1 Tables 1 through 3 present reported exposure levels found in the literature for the 

three major categories of exposure. It should be noted that the sampling periods (when 

available) differ in the different studies with the higher air concentrations seen during short 

sampling periods (e.g., 5 minutes or 15 minutes). The values in these tables illustrate that typical 

time weighted average (TWA) exposures in open-vapor/aerosol systems are < 10 ppm, openvapor systems are about 1 ppm, while similar exposures in closed-vapor systems are < 1 ppm. 

These values would be compared to the proposed permissible exposure limit (PEL) in contrast to 

a peak exposure value of 280 mg/m3 or 69.06 ppm. 

Table 1 -- Open System Vapor/Aerosol

Occupation Exposure Value 

(sampling period) 

Comments Reference

Graffiti removal 9.9 mg/m3or 2.4 

ppm (15 min) 

NMP detected in 

one of 12 samples; 

Sweden 

Anundi 1993 at 

248 

Graffiti removal 0.03-4.52 mg/m3

or 0.007-1.1 ppm 

(8 hr time 

weighted average 

[TWA]) 

Sweden Anundi 2000 at 

564 

Graffiti removal 0.01-24.61 mg/m3

or 0.002-6.07 ppm 

(15 min) 

Sweden Anundi 2000 at 

565 

Graffiti removal 0.01- 30 mg/m3or 

0.002-7.3 ppm 

UK; time period 

for sampling not 

presented 

Cocker 2004

Table 2 -- Open System Vapor

Occupation Exposure Value 

(sampling period) 

Comments Reference

Dipping for paint 

stripping and 

degreasing 

0.01- 6 mg/m3or 

0.002-1.5 ppm 

UK; time period 

for sampling not 

presented 

Cocker 2004

Paint stripping 64 mg/m3or 15.6 

ppm 

Sweden; specific 

study data not 

presented in 

SCOEL 2007 

Åkesson and 

Jönsson, 2000a as 

reported in SCOEL 

2007 at 2 

Paint stripping 280 mg/m3or 

69.06 ppm (peak 

exposure) 

Sweden; specific 

study data not 

presented in 

Åkesson and 

Jönsson, 2000a as 

reported in SCOEL 

 

1

 SCOEL (2007) at 2. 
DRAFT 

NMP Exposure Information 

Page 2 

Table 2 -- Open System Vapor

Occupation Exposure Value 

(sampling period) 

Comments Reference

SCOEL 2007 2007 at 2

Paint stripping 

company 

1.0-3.8 mg/m3or 

0.24-0.93 ppm 

Germany; time 

period of sampling 

not stated 

Will 2004

Adhesive bonding 

compound and 

glue 

manufacturing 

0.9-15.5 mg/m3

0.22-3.8 ppm (8 hr 

TWA) 

Germany Bader 2006 at 362

Adhesive bonding 

compound and 

glue 

manufacturing 

85 mg/m3or 20.7 

ppm (max 5 min) 

Germany Bader 2006 at 363

Table 3 -- Closed System Vapor

Occupation Exposure Value 

(sampling period) 

Comments Reference

Washing lenses 

and wires 

0.04-0.69 ppm (12 

hr TWA) 

Two different 

factories in Japan 

Xiaofei 2000 at 

321 

Microelectronics 

industry 

6 mg/m3or 1.5 

ppm 

U.S.; specific 

study details not 

presented in 

SCOEL 2007 

Beaulieu and 

Schmerber, 1991 

as reported in 

SCOEL 2007 at 2 
{0602.002 / 111 / 00095994.DOC} 1

REFERENCES 

Åkesson, B. and Jönsson, B. (2000). Occupational Study in Paint Stripping Workers. Lund, 

University Hospital, Department of Occupational & Environmental Health. Unpublished report, 

cited in IRCS (2001). 

Anundi, H., Lind, M-L., Friis, L., Itkes, N., Langworth, S., Edling, C. (1993). High Exposures to 

Organic Solvents Among Graffiti Removers. Int. Arch. Occup. Environ. Health 65:247-251.

Anundi, H., Langworth, S., Johanson, G., Lind, M-L., Åkesson, B., Friis, L., Itkes, N., 

Söderman, E., Jonsson, B.A., Edling, C. (2000). Air and Biological Monitoring of Solvent 

Exposure During Graffiti Removal. Int. Arch. Occup. Environ. Health 73:561-569. 

Bader, M. et al. (2006). Ambient Monitoring and Biomonitoring of Workers Exposures to NMethyl-2-Pyrrolidone in an Industrial Facility. Int. Arch. Occup. Environ. Health 79:357-364. 

Beaulieu, H.J., Schmerber, K.R. (1991). M-pyrol (NMP) Use in the Microelectronics Industry. 

Appliedd Occupational and Environmental Hygiene. 6:874-880. 

Cocker, J. et al. (2004). Biological Monitoring of Exposure to N-Methyl-2-Pyrrolidone During 

Graffiti and Paint Removal. 

SCOEL (2007). Recommendations from the Scientific Committee on Occupational Exposure 

Limits for N-Methyl-2-Pyrrolidone. SCOEL/SUM/119 (Aug. 2007). 

Will, W. et al. (2004). Dermal and Inhalative Update of N-Methyl-2-Pyrrolidone (NMP) During 

Paint Stripping of Furniture. Sixth International Symposium of Biological Markers in 

Occupational & Environmental Health (Sept. 6-8, 2004). 

Xiaofei, E. et al. (2000). A Linear Pharmacokinetic Model Predicts Usefulness of N-Methyl-2-

Pyrrolidone (NMP) in Plasma or Urine as a Biomarker for Biological Monitoring for NMP 

Exposure. J. Occup. Heath 42:321-217.