Tris(methylphenyl) phosphate

Health surveillance data

Administrative data

Endpoint:

health surveillance data

Type of information:

other: Published study

Adequacy of study:

key study

Study period:

Not specified

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented, recently published study.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2013

Materials and methods

Study type:

biological exposure monitoring

Endpoint addressed:

not applicable

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

A total of 332 urine samples of pilots and cabin crew members in common passenger airplanes, who reported fume/odour during their last flight, were analysed for three isomers of tricresyl phosphate metabolites as well as dialkyl and diaryl phosphate metabolites of four flame retardants.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of 3-methylphenyl bis(4-methylphenyl) phosphate and bis(3-methylphenyl) 4-methylphenyl phosphate and tris(3-methylphenyl) phosphate

EC Number:

809-930-9

Cas Number:

1330-78-5

Molecular formula:

C21H21O4P

IUPAC Name:

Reaction mass of 3-methylphenyl bis(4-methylphenyl) phosphate and bis(3-methylphenyl) 4-methylphenyl phosphate and tris(3-methylphenyl) phosphate

Details on test material:

Tricresyl phosphates (TCP) from jet engine oils during fume events.

Method

Type of population:

occupational

Ethical approval:

not specified

Details on study design:

A total of 332 urine samples were collected from air crews, pilots and cabin crew members, after reported incidents of smoke/odour. The air crews identified fume events by the smell of stinky socks, oil smell or other smell events. Since TCP metabolites are the only organophosphate levels that should be influenced by fume events and 90 % of p-TCP is excreted within 24 h after oral dose in rats (Kurebayashi et al. 1985), the authors assumed the maximum of excretion within less than 12 h after a reported incident of smoke/odour/ ‘fume event’’ and collected the urine samples within 12 h after exposure.

The study was part of an occupational health examination programme for pilots and cabin crew members.

The authors quantified three metabolites of tricresyl phosphate isomers— oo-, mm-, pp-dicresyl phosphate (DoCP, DmCP, DpCP)—as well as the dialkyl phosphate metabolites of tributyl phosphate (DBP), tris-(2-chloroethyl) phosphate (BCEP), tris-(2-chloroisopropyl) phosphate (BCPP) and triphenyl phosphate (DPP) in urine. Deuterium-labelled internal standards were added to the urine samples. The analytes were separated from the urinary matrix using an ENV+ (crosslinked polystyrene divinylbenzene copolymer) solid-phase column. After derivatisation with 2,3,4,5,6-pentafluorobenzylbromide, a second solid-phase extraction (PSA (silica material with ethylene diamine-Npropyl moieties)-FL(Florisil)) was performed. The extracts were quantified after capillary gas chromatography using tandem mass spectrometry. LODs were 0.2 ug/l for DBP and DPP, 0.1 lg/l for BCEP and BCPP and 0.5 ug/l for DoCP, DmCP and DpCP. Within-series and between-day imprecision were <10 % for all parameters. Spot urines of persons from the general population with no known occupational exposure to organophosphates were used as controls.

Results and discussion

Results:

None of the 332 urine samples contained metabolites of ooo-, oom- or oop-TCP. One urine sample contained m- and p-TCP metabolites close to the LOD (0.5 lg/l).

The analytical method used in this study was sensitive enough to determine the levels of organophosphate metabolites in urine in the sub ug per litre range, which is also indicated by the high percentage of samples > LOD for all parameters besides TCP metabolites.

DBP and DPP were detected in all urine samples of the aircrews. The detection frequencies of BCEP and BCPP were slightly lower (82 and 65 %). Median levels ranged from 0.2 ug/l to 1.1 ug/l for DBP, BCEP, BCPP and DPP. Highest organophosphate levels were found for DPP with more than 300 ug/l. The 95th percentiles were in the low ug per litre range (1.2–6.3 lg/l). Compared to the results from the non-exposed controls of the general population in the authors' previous study, the metabolite levels for TBP, TCEP and TPP but not for TCPP were significantly elevated in the aircrews (p<0.05).

Applicant's summary and conclusion

Conclusions:

A total of 332 urine samples of pilots and cabin crew members in common passenger airplanes, who reported fume/odour during their last flight, were analysed for three isomers of tricresyl phosphate metabolites as well as dialkyl and diaryl phosphate metabolites of four flame retardants. None of the samples contained o-TCP metabolites above the limit of detection (LOD 0.5 ug/l). Only one sample contained metabolites of m- and p-tricresyl phosphates with levels near the LOD.

Executive summary:

A total of 332 urine samples of pilots and cabin crew members in common passenger airplanes, who reported fume/odour during their last flight, were analysed for three isomers of tricresyl phosphate metabolites as well as dialkyl and diaryl phosphate metabolites of four flame retardants. None of the samples contained o-TCP metabolites above the limit of detection (LOD 0.5 ug/l). Only one sample contained metabolites of m- and p-tricresyl phosphates with levels near the LOD. Median metabolite levels of tributyl phosphate (TBP), tris-(2-chloroethyl) phosphate (TCEP) and triphenyl phosphate (TPP) (DBP 0.28 ug/l; BCEP 0.33 ug/l; DPP 1.1 ug/l) were found to be significantly higher than in unexposed persons from the general population. Median tris-(2-chloropropyl) phosphate (TCPP) metabolite levels were significantly not higher in air crews than in controls.

The authors concluded that health complaints reported by air crews can hardly be addressed to o-TCP exposure in cabin air.