Resin acids and Rosin acids, cobalt salts

Explosiveness

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

explosive properties of explosives

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006-08-23 to 2006-08-24

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.14 (Explosive properties)

Version / remarks:

, 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

2006-12-20

Parameter:

other: More sensitive to shock than m-dinitrobenzene

Remarks on result:

not measured/tested

Parameter:

other: More sensitive to friction than m-dinitrobenzene

Remarks on result:

not measured/tested

Parameter:

other: Explosive under influence of flame

Remarks on result:

negative (not further specified)

Parameter:

other: Explosive (not specified)

Remarks on result:

negative (not further specified)

Six negative assays were recorded: No friction sensitivity was noted with the test item with a loading of 360 Newtons.

Six negative assays were recorded: No shock sensitivity was noted with the test item.

Six negative assays were recorded: No heat sensitivity was noted with the test item.

The test item was not considered to have explosive properties in the experimental conditions.

Interpretation of results:

GHS criteria not met

Conclusions:

The test item was not considered to have explosive properties in the experimental conditions.

Reference 2

Endpoint:

explosive properties of explosives

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Qualifier:

according to guideline

Guideline:

other: BS EN 13821:2002 (E) – Determination of minimum ignition energy of dust / air mixtures.

Qualifier:

according to guideline

Guideline:

other: BS EN 14034 Determination of explosion characteristics of dust clouds Part 1: Determination of the maximum explosion pressure and Part 2: Determination of the maximum rate of explosion pressure rise (dp/dt) of dust clouds.

GLP compliance:

yes

Key result

Test series:

other: BS EN 13821:2002 (E)

Method:

other: Minimum Ignition Energy

Parameter:

limiting impact energy (J)

Value:

0.006

Result:

other: dust explosion class: 3

MINIMUM IGNITION ENERGY

The minimum ignition energy of Py Kar has been determined to be in the range of 5 - 6 mJ.

Comment : Ignition produced an orange flame and black smoke.

Full Test Results

Spark Energy (mJ)	Weight Dispersed (g)	Number of Dispersions	Ignition? Yes (y) / No (n)	Flame	Pressure
1000	0.5	1	y	Medium	High
500	0.5	1	y	Medium	Low
100	0.5	1	y	Medium	High
60	0.5	1	y	Large	Medium
40	0.5	1	y	Large	High
25	0.5	1	y	Medium	Medium
15	0.5	20	n	-	-
20	0.5	1	y	Medium	Low
15	1.0	11	y	Medium	Low
10	1.0	11	y	Medium	Low
8	1.0	19	y	Medium	Low
6	1.0	20	n	-	-
6	2.0	20	n	-	-
6	3.0	6	y	Large	High
5	3.0	20	n	-	-
5	5.0	20	n	-	-
5	7.0	20	n	-	-
5	10.0	* 20	n	-	-
5	2.0	20	n	-	-
5	1.0	20	n	-	-
5	0.5	20	n	-	-

* - Full dispersion chamber

EXPLOSION SEVERITY

Pmax = 8.8 bar @ 250 g.m-3

(dP/dt)max = 1139 bar.s-1 @ 250 g.m-3

Kst value = 309 bar.m.s-1

St class = 3

Ambient Temperature = 20°C

Comment

In accordance with the test procedure, the values reported above are the mean values of the maxima found in the three test series.

Full Test Results: mean of test series 1 - 3

Concentration (g.m-3)	Pm (barg)	(dP/dt)m (bar.s-1)
60	6.1	267
125	7.6	749
250	8.8	1139
500	7.7	858
750	6.7	619
1000	6.4	557

Dust Explosion Risk

Minimum Ignition Energy (“MIE”, mJ): 5 - 6

Explosion severity (20 litre sphere):

- Maximum explosion pressure Pmax (bar g): 8.8

- Kst value (bar.m.s-1): 309

- St class: 3

Minimum Ignition Energy (MIE) – Tested ground

20 Litre Sphere Test (20L) – Tested ground

The results of testing are highly dependent on the composition and physical nature of the sample. In dust explosion testing, for example, the particle size distribution, moisture content, particle shape and preparation method can all markedly affect results. For this reason, any change in manufacturing / handling procedures or composition should be accompanied by a review of the relevant data. Chilworth Technology Ltd would be pleased to provide specific advice, including interpretation and application of experimental data. Site visits to discuss operational safety or to perform plant inspections and measurements can be arranged on request.

Conclusions:

Minimum ignition energy testing has shown that this material is very sensitive to ignition from electrostatic discharges (MIE = 5 - 6 mJ).
The 20 L Sphere Test gave a Pmax of 8.8 bar and a Kst value of 309 bar.m.s-1 therefore the sample falls within the St 3 classification or high explosion severity potential.

Executive summary:

Interpretation of Results and Recommendations

Minimum ignition energy testing has shown that this material is very sensitive to ignition from electrostatic discharges (MIE = 5 - 6 mJ), therefore spark discharges from isolated personnel, metal conductors (including metal hand tools such as scoops and knifes as well as larger equipment), conductive process materials and propagating brush discharges (produced from thin insulating materials in close proximity to an earthed conductor) will present a risk.

This characteristic implies the need for extreme caution in the avoidance of electrostatic ignition sources. This should include, but is not limited to:

- Minimisation of charging mechanisms (use of low energy handling methods and slow transfers).

- Rigorous earthing of plant, personnel and conductive process materials.

- Avoidance of large scale storage (eg. in silos or volumes greater than 1m³) of insulating powders or granules to minimise charge accumulation and reduce the possibility of cone discharges.

If avoidance of ignition sources is employed as the basis of safety, a careful and rigorous identification and mitigation of ignition sources (including non-electrostatic ignition sources) should be undertaken. If not already known it is recommended this materials electrostatic properties are evaluated to assess its ability to accumulate and retain hazardous levels of charge (powder volume resistivity & charge relaxation time testing).

The MIE of a material is highly sensitive to temperature. If data obtained at ambient temperature is applied to an elevated temperature processing environment, a suitable safety margin should be employed. Published correlations exist regarding applicable correction factors.

The 20 L Sphere Test gave a Pmax of 8.8 bar and a Kst value of 309 bar.m.s-1 therefore the sample falls within the St 3 classification or high explosion severity potential. It should be borne in mind that owing to the non uniformity of dust clouds, a repeat of the test could cause the Kst value to fluctuate by ± 10 %. Consideration must be given to this if applying the data for use in explosion protection / prevention measures.

As the Kst has been found to be in the St 3 category (high explosive severity potential) then it may be prudent to consider inert gas blanketing as a basis of safety. The Limiting Oxygen Concentration test would define the oxygen concentration below which dispersed dust ignition is not possible. The data obtained can be used directly in the sizing of explosion vent or containment systems. It is usually found that there is some correlation between explosion severity and ignition sensitivity. If avoidance of ignition sources forms part of the basis of safety for handling Py Kar, consideration should be given to the conduct of ignition sensitivity tests.

Description of key information

Resin acids and rosin acids, cobalt salts was not considered to have explosive properties in the experimental conditions.

Key value for chemical safety assessment

Explosiveness:

non explosive

Justification for classification or non-classification

Resin acids and Rosin acids, cobalt salts does not need to be classified according to CLP Regulation (EC) No 1272/2008.