Dimethoxymethane

Density

Description of key information

The pieces of information that build the weight of evidence are the following:

A) Publication from Palomaa (1937)       

Purity not specified and method not described       

Value of denisty: 0.8608 at 20°C

B) Handbook from Flick (1991)       

Purity of min. 97%       

Method not described       

Value of denisty: 0.8601 at 20°C

C) Publication from Reddy et al. (2004)       

Purity of 99.5% (Merck Company)       

Description of method and apparatus (bicapillary pycnometer)       

Value of denisty: 0.84751 at 25°C

D) Publication from Ren et al. (2007)       

Purity >99.0% (Chaoyang Chemical Co. Ltd.)       

Description of method and apparatus (pycnometer)       

Value of denisty: 0.849 at 28°C

E) Publication from Francescioni et al., 1994       

Purity of 99%       

Description of method and apparatus (Anton Paar density meter)       

Value of denisty: 0.86648 at 15°C

F) Publication from Francescioni et al., 1993       

Purity of 99% (Aldrich) and then purified by two fractional distillations through 120 theoretical plate column       

Description of method and apparatus (2-capillary glass pycnometer)

Density = 885.3-1.2629 x (T – 273.15)

Density in kg/m3

Temperature in K

Range of T tested: [288.15K; 303.15K]

Or [15°C; 30°C]

σ: 0.07

Values of denisty:

0.8499 at 28°C

0.8538 at 25°C

0.8600 at 20°C

0.8664 at 15°C

G) Publication from Wu et al., 2005       

Purity >99.4%

Description of method and apparatus (vibrating-tube densimeter)

Range of T tested: [-40°C; 90°C]

Value of denisty: 0.8581 at 20°C

Key value for chemical safety assessment

Relative density at 20C:

0.861

Additional information

The weight of evidence approach is justified as determined from more than one piece of information (independent sources). We claim the reliability, relevance, adequacy and quality of the weight of evidence:

-     Reliability: Klimisch score of 2 is assigned to the studies 

-     Relevance:

o  Relevance of test material: substance purity ranges from 97% to 99.5% without affecting the reproducibility of the endpoint value. The test material is equivalent to the submission substance identity.

o  Relevance of test method and conditions: the tested methods are described enough to demonstrate their comparability with internationally approved test guidelines.

o  Relevance of the endpoint: the values obtained extend over 70 years and show a good reproducibility.

Source	Density value at temperature of
	15°C	20°C	25°C	28°C
Palomaa (1937)		0.8608
Flick (1991)		0.8601
Reddy et al. (2004)			0.84751
Ren et al. (2007)				0.849
Francescioni et al., 1994	0.86648
Francescioni & Comelli, 1993	0.8664	0.8600	0.8538	0.8499
Wu et al., 2005		0.8581

-     Adequacy: the endpoints, whereas obtained from not internationally approved test guideline, with different sources and purity of test item and at different temperatures, lead to a clear trend: density of dimethoxymethane is 0.861 at 20°C

-     Quantity: seven pieces of information are considered.