Chemwatch : 34-9547 Version No : 5.1.1.1
Page 6 of 15 Fido ' s Flea Bomb
Issue Date : 05 / 31 / 2016 Print Date : 06 / 27 / 2016 propane 20,000 [ LEL ] ppm 2,100 [ LEL ] ppm butane Not Available Not Available
MATERIAL DATA
For liquefied petroleum gases ( LPG ): TLV TWA : 1000 ppm , 1800 mg / m3 ( as LPG ) ES TWA : 1000 ppm , 1800 mg / m3 ( as LPG ) OES TWA : 1000 ppm , 1750 mg / m3 ; STEL : 1250 ppm , 2180 mg / m3 ( as LPG ) IDLH Level : 2000 ppm ( lower explosive limit ) No chronic systemic effects have been reported from occupational exposure to LPG . The TLV-TWA is based on good hygiene practices and is thought to minimise the risk of fire or explosion . Odour Safety Factor ( OSF ) OSF = 0.16 ( hydrocarbon propellant )
For butane : Odour Threshold Value : 2591 ppm ( recognition ) Butane in common with other homologues in the straight chain saturated aliphatic hydrocarbon series is not characterised by its toxicity but by its narcosis-inducing effects at high concentrations . The TLV is based on analogy with pentane by comparing their lower explosive limits in air . It is concluded that this limit will protect workers against the significant risk of drowsiness and other narcotic effects . Odour Safety Factor ( OSF ) OSF = 0.22 ( n-BUTANE )
For pyrethrum and its active components : IDLH Level : 5000 mg / m3 Pyrethrum and / or its active components , the pyrethrins , cause dermatitis and sensitisation . Ingestion of massive doses can induce convulsions , vomiting and bradycardia . Animals exhibit liver damage and death through respiratory failure . The recommended TLV-TWA is equivalent to an occupational dose of 0.7 mg / kg / day and is thought to minimise the potential for systemic effects . The TLV may NOT prevent the development of hypersensitisation , particularly among those with pre-existing allergies to pollen and related agents . Synthetic pyrethrins ( pyrethroids ) often produce a range of toxic effects resembling pyrethrum ; in the absence of a regulated exposure limit prudence dictates that the value for pyrethrum serves as a reference .
Exposure controls
Engineering controls are used to remove a hazard or place a barrier between the worker and the hazard . Well-designed engineering controls can be highly effective in protecting workers and will typically be independent of worker interactions to provide this high level of protection . The basic types of engineering controls are : Process controls which involve changing the way a job activity or process is done to reduce the risk . Enclosure and / or isolation of emission source which keeps a selected hazard " physically " away from the worker and ventilation that strategically " adds " and " removes " air in the work environment . Ventilation can remove or dilute an air contaminant if designed properly . The design of a ventilation system must match the particular process and chemical or contaminant in use . Employers may need to use multiple types of controls to prevent employee overexposure .
General exhaust is adequate under normal conditions . If risk of overexposure exists , wear SAA approved respirator . Correct fit is essential to obtain adequate protection . Provide adequate ventilation in warehouse or closed storage areas . Air contaminants generated in the workplace possess varying " escape " velocities which , in turn , determine the " capture velocities " of fresh circulating air required to effectively remove the contaminant .
Type of Contaminant : Speed :
Appropriate engineering controls aerosols , ( released at low velocity into zone of active generation )
direct spray , spray painting in shallow booths , gas discharge ( active generation into zone of rapid air motion )
Within each range the appropriate value depends on :
0.5-1 m / s
1-2.5 m / s ( 200-500 f / min .)
Lower end of the range
Upper end of the range 1 : Room air currents minimal or favourable to capture 1 : Disturbing room air currents 2 : Contaminants of low toxicity or of nuisance value only . 2 : Contaminants of high toxicity 3 : Intermittent , low production . 3 : High production , heavy use 4 : Large hood or large air mass in motion 4 : Small hood-local control only
Simple theory shows that air velocity falls rapidly with distance away from the opening of a simple extraction pipe . Velocity generally decreases with the square of distance from the extraction point ( in simple cases ). Therefore the air speed at the extraction point should be adjusted , accordingly , after reference to distance from the contaminating source . The air velocity at the extraction fan , for example , should be a minimum of 1-2 m / s ( 200-400 f / min .) for extraction of solvents generated in a tank 2 meters distant from the extraction point . Other mechanical considerations , producing performance deficits within the extraction apparatus , make it essential that theoretical air velocities are multiplied by factors of 10 or more when extraction