JAN 31 1991

MEMORANDUM FOR:   JAMES LAKE
                 REGIONAL ADMINISTRATOR

FROM:             PATRICIA K. CLARK, DIRECTOR
                 DIRECTORATE OF COMPLIANCE PROGRAMS

SUBJECT:          Interpretation of 29 CFR 1910.109 Relative to
                 Peroxides and Chlorates in Blasting Agents, 
                 Slurries, and Emulsions

The Occupational Safety and Health Administration (OSHA) does not approve or certify end products.

We will answer the questions in the order that they were presented. First, does 29 CFR 1910.109(h)(3)(iii)(e) apply to ammonium nitrate based emulsion type blasting agents and explosives? Yes, 29 CFR 1910.109(h) applies to these blasting agents, water gel (slurry), and emulsion type explosive materials.

Second, regarding the prohibition of peroxides and chlorates in blasting agents, 29 CFR 1910.109(h)(3)(iii)(e) prohibits peroxides and chlorates as part of the oxidizer system of these materials.

Third, what percent concentration of peroxide chlorate is permissible in water gel-slurry explosives and blasting agents, if not part of the oxidizer system? OSHA has no specific permissible concentration of peroxide or chlorate in water gel- slurry explosives and blasting agents not part of the oxidizer system.

Fourth, is it permissible to add small amounts of peroxides or chlorates to blasting agents, if they decompose harmlessly within a short period of time? No, 29 CFR 1910.109(h)(3)(iii)(e) prohibits any addition or use of peroxides or chlorates. How long a decomposition time would be acceptable? OSHA has not set a decomposition time limit.

Fifth, is it permissible to use in water gel blasting agents or explosives small amounts of chemicals which may be peroxide or chlorate at some time...? 29 CFR 1910.109(h)(3)(iii)(e) again prohibits the use of peroxides or chlorates in blasting agents and explosive materials.

Attachments

GICA:SAA:LPolito:tf:12-13-90:file #saa.62l corliss comp. dcp#1922 cc:Clark,Donnelly,Stroup,Polito,HRT,OTI,OCIS,CHRON