chloromethane; methyl chloride

Epidemiological data

Administrative data

Endpoint:

epidemiological data

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Only secondary literature

Data source

Reference

Reference Type:

publication

Title:

A mortality study of employees at a synthetic rubber manufacturing plant.

Author:

Holmes, T. M. et al.

Year:

1986

Bibliographic source:

Am J Ind Med. 1986;9(4):355-62, as cited in: OECD SIDS Chloromethane, 2004

Materials and methods

Study type:

cross sectional study

Endpoint addressed:

carcinogenicity

Principles of method if other than guideline:

A mortality follow-up study was conducted of workers employed at a synthetic rubber manufacturing plant in Baton Rouge, Louisiana. Interest in the potential health effects of exposure to methyl chloride, one of the substances used in the manufacturing process, provided the impetus for this study.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Chloromethane

EC Number:

200-817-4

EC Name:

Chloromethane

Cas Number:

74-87-3

Molecular formula:

CH3Cl

IUPAC Name:

chloromethane

Details on test material:

- Name of test material (as cited in study report): methyl chloride
- Analytical purity: no data

Method

Type of population:

occupational

Ethical approval:

not specified

Details on study design:

The study cohort consisted of 852 male process workers who had worked at least 1 month during the period from startup of operations in 1943 through December 31, 1978.

Exposure assessment:

not specified

Results and discussion

Results:

Mortality from all causes was lower than expected when compared with the U.S. male population. No excess mortality from any specific cause of death was found in the study population after analysis by level and duration of exposure.
There was no increase in deaths due to cancer in this study population, but the study has only limited statistical power.  
External causes of death were too few to calculate significance.  
In general, less than expected mortality occurred in every category and no cause of death was in statistical excess.  

Strengths and weaknesses:

The authors noted the small size and low  power of their study.

Any other information on results incl. tables

TABLE 1

Observed and Expected* Deaths From Selected Causes Among White Male Butyl Rubber Workers First Employed In Butyl Rubber Operations During the Period 1943-1950 by Potential for Exposure to Methyl Chloride

 

Cause of Death (ICD-8th rev)	Low		Medium		High
	Obs/Exp	SMR^**	Obs/Exp	SMR	Obs/Exp	SMR
All causes (001-998)	7 / 12.6	56	16 / 22.1	72	69 / 77.5	89
Malignant neoplasms (140-209)	1 / 2.4	42	2 / 4.4	45	10 / 15.5	65
Circulatory system diseases (390-458)	3 / 6.3	48	10 / 11.0	91	43 / 40.0	108
External causes of death (800-998)	2 / 1.5	133	3 / 2.3	30	7 / 7.0	100

* Expected numbers are based on calendar time and age-specific mortality rates of white males.

^**(Observed/expected) x 100. (Holmes, et al., 1986).