The rapporteur is asking for a threshold of 50 to 30 ppm, which would also involve excessive cost without appreciable benefit.
1	The	the	DET	DEF	Definite=Def|PronType=Art	2	det	_	_
2	rapporteur	rapporteur	NOUN	SG-NOM	Number=Sing	4	nsubj	_	_
3	is	be	AUX	PRES-AUX	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	4	aux	_	_
4	asking	ask	VERB	ING	Tense=Pres|VerbForm=Part	0	root	_	_
5	for	for	ADP	_	_	7	case	_	_
6	a	a	DET	IND-SG	Definite=Ind|PronType=Art	7	det	_	_
7	threshold	threshold	NOUN	SG-NOM	Number=Sing	4	obl	_	_
8	of	of	ADP	_	_	12	case	_	_
9	50	50	NUM	CARD-PL	NumType=Card	12	nummod	_	_
10	to	to	ADP	_	_	11	case	_	_
11	30	30	NUM	CARD-PL	NumType=Card	9	nummod	_	_
12	ppm	ppm	NOUN	PL-NOM	Number=Plur	7	nmod	_	SpaceAfter=No
13	,	,	PUNCT	Comma	_	17	punct	_	_
14	which	which	PRON	WH-REL	PronType=Rel	17	nsubj	_	_
15	would	would	AUX	PAST-AUX	VerbForm=Fin	17	aux	_	_
16	also	also	ADV	_	_	17	advmod	_	_
17	involve	involve	VERB	INF	VerbForm=Inf	7	acl	_	_
18	excessive	excessive	ADJ	POS	Degree=Pos	19	amod	_	_
19	cost	cost	NOUN	SG-NOM	Number=Sing	17	obj	_	_
20	without	without	ADP	_	_	22	case	_	_
21	appreciable	appreciable	ADJ	POS	Degree=Pos	22	amod	_	_
22	benefit	benefit	NOUN	SG-NOM	Number=Sing	17	obl	_	SpaceAfter=No
23	.	.	PUNCT	Period	_	4	punct	_	_
