Zinc methacrylate

Additional physico-chemical information

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

other: Dust explosivity

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

26 July 1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

This study was reliable with restriction because we have not information on the purity and the identification of the test item.

Qualifier:

according to guideline

Guideline:

other: explosion protection systems 1986 equivalent to BS 6713

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

other: BS 5958 Part 1: 1991 Control of Undesirable static electricity

GLP compliance:

not specified

Results:

The results of data explosion were:
-Maximum Explosion Pressure (Pmax): 7.4 bar
-Max. Rate of pressure Rise (dP/dt)max: 519 bar/s
-Kst value: 141 bar.m/s : The relationship between Kst value and the physical severity of the dust explosion:weak explosion
The result of Minimum ignition of energy: According to the table of guide to electrostatic precautions for powders, as the minimum energy ignition is between 10 -25mJ, the precautions are:
At 25mJ: "the majority of ignition incidents occur when ignition energy is below this level. The hazard from electrostatic discharges from dust clouds should be considered"
At 10mJ: "High sensitivity to ignition. Take the above precautions and consider restrictions on the use of high resistivity materials (plastics). Electrostatic hazard from bulk powders of high resistivity should be considered. "
Minimum Oxygen concentration:12.0 -15.0 %

Results of explosion data:

Series 1:

Test No	Concentration (g/m3)	Pressure (bar)	Rate of pressure rise (bar/s)
1 2 3 4 5 6 7 8	250 500 750 1000 1500 2000 1250 1750	3.7 7.5 7.2 7.4 6.9 6.3 7.4 6.7	148 445 478 460 521 479 438 419

Series 2:

Test No	Concentration (g/m3)	Pressure (bar)	Rate of pressure rise (bar/s)
9 10 11 12 13	250 500 750 1000 1250	4.3 6.6 7.2 7.5 7.0	166 323 380 529 278

Series 3:

Test No	Concentration (g/m3)	Pressure (bar)	Rate of pressure rise (bar/s)
13 14 15	1250 1500 1750	7.1 7.1 6.4	506 447 442

Test series (mean values)

Concentration (g/m3)	Pressure (bar)	Rate of pressure rise (bar/s)
250 500 740 1000 1250 1500 1750 2000	3.9 7.0 7.2 7.4 7.2 7.0 6.5 6.3	157 384 429 495 407 484 431 479

Maximum Explosion Pressure (Pmax): 7.4 bar

Max. Rate of pressure Rise (dP/dt)max: 519 bar/s

Kst value: 141 bar.m/s

These explosion data only refer to the sample tested. Sample of different particle size distribution and moisture content may yield different results. The above results are the mean of maximum values.

Moisture content: 0.2% by weight

Weight of sample (g)    weight after drying (g) Moisture loss (g) Moisture loss (%)

10.00                                   9.98                          0.02                             0.2 10.00                                    9.98                               0.02                             0.2

During testing of powders in the 20l sphere test to BS6713 and ISO6184/1 1985 a minimum of seven different concentrations are tested, this is presented as three tables of results.

A fourth table is produced to represent the mean values for each of the concentrations tested.

The final quoted values for Pressure, Rate of Pressure Rise and Concentration are calculated from the mean of the maximum values during test series 1,2 & 3 in accordance with the 20l sphere test protocol.

Maximum valued are not quoted. The average result over the three series is given. This is because slight variations in turbulence or chemical ignitor energy may marginally effect the results.

It should be borne in mind that the standart test does not provide the maximum rate of pressure rise; a decrease in ignition delay will give higher maximum rate of pressure rise data. The turbulence level is selected to correlate with data from large (industrial scale) vessels. The Cube Root Law on which the 20l sphere test is based, assumes that on plant scale, the dust suspension is quiescent, i.e, negligible turbulence.

The relationship between Kst value and the physical severity of the dust explosion is given by the following table.

Kst (bar ms-1)	Characteristics
0 0-200 201-300 >300	No explosion Weak explosion Strong explosion Very strong explosion

Minimum Ignition Energy:

10 -25mJ

Spark energy (mJ)	Weight Dispersed (g)	No of tests	Ignition	Flame size	Pressure Size
C/A C/A C/A 500 300 100 50 50 25 10 10 10 10 10 10	0.5 1.0 2.0 1.0 1.0 1.0 1.0 2.0 2.0 2.0 4.0 6.0 8.0 10.0 12.0	1 1 1 1 3 2 20 15 11 20 20 20 20 20 20	Yes Yes Yes Yes Yes Yes No Yes Yes No No No No No No	Large V.Large V.Large Large V.Large V.Large - Large Large - - - - - -	High V.High V.High V.High V.High High - - - - - - - - -

Note: C/A = Constant Arc from 10kV transformer

Minimum ignition energy determination is a statistical test in which a (possibly non-uniform) dust cloud is created in the laboratory apparatus. If a series of repeat measurements was performed on a single powder, a spreadof results would therefore be expected. Changes in some parameters are know to produce changes in the measured MIE of powders. Parameters which are know to affect Minimum ignition energy include chemical composition, particle size and moisture content. It is essential that powder samples provided for testing are representative of plant material. According to the table of guide to electrostatic precautions for powders, as the minimum energy ignition is between 10-25mJ, the precautions are:

At 25mJ: "the majority of ignition incidents occur when ignition energy is below this level. The hazard from electrostatic discharges from dust clouds should be considered"

At 10mJ: "High sensitivity to ignition. Take the above precautions and consider restrictions on the use of high resistivity materials (plastics). Electrostatic hazard from bulk powders of high resistivity should be considered. "

Minimum Oxygen concentration:12.0 -15.0 %

Oxygen Conc. (%)	Weight Dispersed (g)	No of trials	Ignition	Flame size	Pressure
20.9 15.0 12.0 12.0 12.0 12.0 12.0 12.0	0.5 0.5 0.5 1.0 2.0 5.0 8.0 12.0	1 1 10 10 10 10 10 10	Yes Yes No No No No No No	Med Med - - - - - -	Med Low - - - - - -

In applying this result to your process, it is advisable to incorporate a safety factor. Where the oxygen concentration is continuously monitored, a safety factor of 2% is generally recommended. Where oxygen concentration is not continuously monitored, the oxygen concentration within the vessel or area should not exceed 60% of the MOC.

Conclusions:

The results of data explosion were:
-Maximum Explosion Pressure (Pmax): 7.4 bar
-Max. Rate of pressure Rise (dP/dt)max: 519 bar/s
-Kst value: 141 bar.m/s : The relationship between Kst value and the physical severity of the dust explosion:weak explosion
The result of Minimum ignition of energy: According to the table of guide to electrostatic precautions for powders, as the minimum energy ignition is between 10 -25mJ, the precautions are:
At 25mJ: "the majority of ignition incidents occur when ignition energy is below this level. The hazard from electrostatic discharges from dust clouds should be considered"
At 10mJ: "High sensitivity to ignition. Take the above precautions and consider restrictions on the use of high resistivity materials (plastics). Electrostatic hazard from bulk powders of high resistivity should be considered. "
Minimum Oxygen concentration:12.0 -15.0 %

Executive summary:

This study was performed in order to determine the results of dust explosibility according to the explosion protection systems 1986 equivalent to BS 6713 and BS 5958 Part 1: 1991 Control of Undesirable static electricity.

The results of data explosion:

-Maximum Explosion Pressure (Pmax): 7.4 bar

-Max. Rate of pressure Rise (dP/dt)max: 519 bar/s

-Kst value: 141 bar.m/s : The relationship between Kst value and the physical severity of the dust explosion:weak explosion

The result of Minimum ignition of energy: According to the table of guide to electrostatic precautions for powders, as the minimum energy ignition is between 10 -25mJ, the precautions to take are :

At 25mJ: "the majority of ignition incidents occur when ignition energy is below this level. The hazard from electrostatic discharges from dust clouds should be considered"

At 10mJ: "High sensitivity to ignition. Take the above precautions and consider restrictions on the use of high resistivity materials (plastics). Electrostatic hazard from bulk powders of high resistivity should be considered. " Minimum Oxygen concentration:12.0 -15.0 % (Ogle, 1996).

Reference 2

Endpoint:

other: Dust explosivity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11 October 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: EN 14034 "Determination of explosion characteristics of dust clouds

Deviations:

not specified

Principles of method if other than guideline:

Principle of the Test Method
A defined amount of dust with a particle size below 63 µm is dispersed from a dust container by an overpressure air blast. At the commencement of the dust dispersion the pressure in the 20 dm³ vessel is at atmospheric pressure. The actual pressure in the 20 dm³ vessel at the moment of ignition (initial pressure pi) is measured and recorded. The explosion tests with defined dust/air mixtures are carried out according to the following procedure: The required amount of the dust is placed in the dust container. The container is then pressurised to an overpressure. At the commencement of the dust dispersion the pressure in the 20 dm³ vessel shall be at atmospheric pressure. After dispersion of the dust by the overpressure into the 20 dm³ vessel, the air dust mixture is ignited. The ignition is performed with two electrically activated pyrotechnical igniters, each having an ignition energy of 2 kJ (this is the nominal calorimetric energy based on the mass of pyrotechnic powder in the igniters).  The actual pressure in the 20 dm³ vessel at the moment of ignition (initial pressure pi) is measured and recorded and the pressure rise is the criterion for the existence of an explosion.

GLP compliance:

yes (incl. QA statement)

Results:

The measured overpressure relative to the initial pressure (pm) is in three tests significantly above 0.3 bar between O and 750g/cm3.
Therefore, the test item Zinc methacrylate is identified as dust explosible

List of Measurement Results: Table 1: List of Explosion Tests

(Serie) Test	Konz. [g/m3]	Pm [bar]	dP/dt [bar/s]	t1 [ms]	Tv eff [ms]	Z [J]
(-) 1 (1) 2 (1) 3 (1) 4	0 500 750 250	,0 7,1 7,7 4,2	0 409 516 154	57 64 45 91	59 60 60 60	2k 2k 2k 2k

Konz.: concentration

p_m:        overpressure

dp/dt:  pressure rise

tv eff:  ignition delay

Z:         ignition energy

Calculation

The measured overpressure relative to the initial pressure (p_m) is in three tests significantly above 0.3 bar. The test item Zinc methacrylate (CAS 13189-00-9 Einecs No. 236-144-8) is identified as dust explosible

Conclusions:

The measured overpressure relative to the initial pressure (pm) is in three tests significantly above 0.3 bar. Therefore, the test item Zinc methacrylate is identified as dust explosible.

Executive summary:

This study was performed in order to determine the dust explosivity of the test item Zinc methacrylate according to EN 14034 "Determination of explosion characteristics of dust clouds" using the 20 l Stainless Steel Sphere under GLP. Dust Explosibility is given if a substance as raised dust is explosible in a wide range of dust concentrations (30 – 2000 g/m³) when ignited by a chemical igniter with an energy of 2 kJ. A pressure rise of >=0.3 bar (Pm) at one concentration is the necessary criterion for explosibility. For determining the dust explosibility the procedure is started with a medium dust concentration and repeated by decreasing and increasing the dust concentration by stepwise change of the preceding concentration 1000; 750; 500; 250; 125; 60 g/m³. The measured overpressure relative to the initial pressure (pm) is in three tests significantly above 0.3 bar. Therefore, the test item Zinc methacrylate is identified as dust explosible (Butfering, 2012).

Description of key information

The measured overpressure relative to the initial pressure (pm) was in three tests significantly above 0.3 bar.

Therefore, the test item Zinc methacrylate is identified as dust explosible

Additional information

A study was performed to determine the dust explosivity of zinc methacrylate. The measured overpressure relative to the initial pressure (pm) was in three tests significantly above 0.3 bar

Additionals data explosion were performed to measure:

-Maximum Explosion Pressure (Pmax): 7.4 bar

-Max.Rate of pressure Rise (dP/dt)max: 519 bar/s

-Kst value: 141 bar.m/s : The relationship between Kst value and the physical severity of the dust explosion is weak explosion

-Minimum Ignition Energy: 10-25mJ